EP4537369A1

EP4537369A1 - Permanent magnets with enhanced coercivity

Info

Publication number: EP4537369A1
Application number: EP23733238.2A
Authority: EP
Inventors: Mogens Christensen; Anna ZINK EIKELAND; Harikrishnan Vijayan Pillai
Original assignee: Aarhus Universitet
Current assignee: Aarhus Universitet
Priority date: 2022-06-10
Filing date: 2023-06-09
Publication date: 2025-04-16
Also published as: JP2025519252A; KR20250022718A; WO2023237760A1

Abstract

The present invention relates to a method of producing a bulk magnetic material of permanent magnets free of rare-earth metals. Specifically the type of magnets produced by the present invention are rare-earth free magnets based on iron. More specifically, the magnets of the present invention are of the class hexaferrites. The present invention further relates to magnets produced by the method of the invention, which feature misaligned magnetic moments resulting in improved magnetic properties such as higher coercivity.

Description

Permanent magnets with enhanced coercivity

Technical field

Background

Permanent magnets are an essential components in a wide range of industrial processes, scientific research setups and daily life objects. Industries such as the semiconductor, automotive, peripheral terminal devices or large-scaled computers heavily rely in the supply of strong permanent magnets. Their fabrication require high energy consuming processes, both in the ore extraction and purification, and during the magnetization.

Such powerful magnets are at the present almost exclusively rare-earth magnets such as the NIB magnets, a common term used for the NdFeB (or NdsFe^B) type magnets. While the magnetic properties of NIB magnets are highly desirable, the high cost of rare-earth ore, and environmental apprehension associated with mining and recycling of these elements have sparked an interest in rare-earth-free permanent magnets, such as the hexaferrites, as a cheap and plentiful alternative, while also promising to be less environmentally straining.

Evidently, there remains a need in the art for an efficient way to produce rare-earth-free permanent magnets, such as the hexaferrites with enhanced magnetic properties using industrially viable methods and resources. Summary

The present invention relates to a method of making permanent magnets free of rare- earth metals. Specifically the type of magnets produced by the present invention are rare-earth free magnets based on iron. More specifically, the magnets of the present invention are of the class hexaferrites.

The present inventors have devised a new manufacturing method which allows for controlled misalignment of magnetic moments in bulk magnetic materials, specifically hexaferrite materials. As such, the method allows for the production of novel bulk magnetic materials which are characterized by comprising at least two distinct magnetic parts, which are not aligned with respect to each other.

One aspect of the present invention is thus directed to a method for manufacturing a bulk magnetic material of hexaferrite, the bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, each part comprising or consisting of M-type strontium hexaferrite (SrFeisO ), the method comprising the steps: a. Providing a first iron-based oxide comprising anisotropic crystallites, the anisotropic crystallites characterized by an average aspect ratio A/C is 5 to 500; b. Providing a second iron-based oxide in the form of M-type strontium hexaferrite (SrFeisO ), the second iron-based oxide comprising crystallites, the crystallites characterized by an average aspect ratio A!C < 3; c. Providing an amount of an alkaline earth metal (aem) precursor; d. Mixing said first and said second iron-based oxides with said alkaline earth metal (aem) precursor to obtain a final precursor mixture; e. Compacting said final precursor mixture by the application of uniaxial pressure of 200 MPa of 5000 MPa, thereby inducing alignment of the first iron-based precursor while the second iron-based precursor is not aligned by this step, to obtain a partially aligned precursor; f. Heating said partially aligned precursor, at a heating rate ranging from 10 °C/h to 10 °C/min, to a temperature ranging from 1000 °C to 1240 °C, to convert said partially aligned precursor into said bulk magnetic material of hexaferrite; and g. Isolating the thus formed bulk magnetic material of hexaferrite comprising an aligned magnetic part and a non-aligned magnetic part from the reaction mixture, each part comprising or consisting of M-type strontium hexaferrite (SrFeisO ).

Taking advantage of the anisotropic crystallite shape of the first iron-based oxide in combination with the non-anisotropic crystallite shape of the second iron-based oxide as described below, the inventors demonstrate that it is possible, using only pressure and no external magnetic field, to align the crystallites of the first iron-based oxide in a preferred orientation while leaving the crystallites of the second iron-based oxide largely unaffected, which in turn facilitates formation of a bulk magnetic material during calcination, which features misaligned magnetic moments and as a result improved magnetic properties such as increased coercivity.

Thus, a second aspect of the present invention is directed to a bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites; wherein the aligned magnetic part is uniformly aligned, and wherein the non-aligned magnetic part is not aligned, neither uniformly, nor with respect to the aligned magnetic part, and wherein the aligned, and non-aligned magnetic part of hexaferrite comprise or consist of M-type strontium hexaferrite (SrPeisO ).

As a result of the enhanced magnetic properties obtained by the controlled misalignment of magnetic moments in the bulk magnetic material of the present invention, the present disclosure demonstrates a broad and useful potential in replacement of other ferrite materials or NIB rare-earth magnets. It is an aspect of the present invention that the bulk magnetic material of the present invention does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y).

Further aspects of the present invention relates generally to the bulk magnetic materials as described herein below for use as a magnetic component in various devices, such as in electric motors. While not as important as the anisotropic morphology, the first iron-based oxide is preferably also non-ferromagnetically interacting in nature. When the first iron-based oxide is non-ferromagnetically interacting, the risk of magnetic domain short-circuiting is eliminated during the production step of the hexaferrite permanent magnet, which would otherwise require heating above the Curie temperature of the precursor, such as e.g., by the application of spark plasma sintering (SPS) or alternatively application of large magnetic fields to break the ferromagnetic interaction. Both of these are undesirable in terms of industrial scale-up, and so it is beneficial to eliminate these needs.

Consequently, by utilizing a non-ferromagnetic nature in the first iron-based oxide in combination with both anisotropic and non-anisotropic crystallites as described herein, it is possible to produce bulk magnetic materials, such as rare-earth free magnets with improved magnetic properties such as improved coercivity in an industrially relevant scale and cost.

Another advantage of the presently claimed production method is that there is virtually no size-limitation to the magnets produced. In cases where external magnetic fields are needed, the size of the magnet is limited by how large a homogeneous magnetic field can be generated which is a serious limiting factors for industrial scalability of very large magnets. For the presently claimed methods however, the magnets can be produced by simple cold compaction (i.e. compaction at room temperature) and without the need for large magnetic fields, which results in the only limiting feature on size is an appropriate pressing tool, which can much more easily be implemented to industrial scale.

Description of Drawings

Figure 1 : standard magnetic M versus H hysteresis loop of A) a non-aligned magnet and B) a highly aligned magnet. M_s, M_r, and H_c are indicated on the figures.

Figure 2: A) schematic representation of the platelet shaped crystallites of the first iron-based oxide, and B) schematic representation of the needle shaped crystallites of the first iron-based oxide. The A and C lengths are indicated by arrows. Figure 3: schematic illustration of the production of bulk magnetic material comprising misaligned magnetic moments according to three embodiments of the invention. Top: the first iron-based oxide is goethite having a needle-shaped crystallite morphology which is mixed with powders of SrFe^O having a spherical crystal morphology (the second iron-based oxide) and also mixed with SrCOs. Upon application of pressure (force), the first iron-based oxide aligns while the second iron-based oxide is largely unaffected. With the application of heat (calcination), the mixture of goethite and strontium carbonate is transformed into magnetically aligned grains of SrFe^O comprising non-aligned (or misaligned) grains of SrFeisO within the matrix. Middle: the first iron-based oxide is goethite having a needle-shaped crystallite morphology which is mixed with powders of hematite having a spherical crystal morphology (the second iron-based oxide) and also mixed with SrCOs. The remaining procedure is analogous to above. Bottom: the first iron-based oxide is six-line ferrihydrite or hematite having a platelet-shaped crystallite morphology which is mixed with powders of SrFeisOig or hematite having a spherical crystal morphology (the second iron-based oxide) and also mixed with SrCOs. The remaining procedure is analogous to above.

Figure 4: a) TEM micrograph of goethite rod like a-FeOOH anisotropic crystallites used as first iron-based oxide, and b) TEM micrograph of NaCI solid-salt-matrix (SSM) synthesized SrFe^O non-anisotropic crystallites used as second iron-based oxide with a characteristic average aspect ratio A/C < 3.

Figure 5: Hysteresis loops of a bulk magnet comprising misaligned domains according to the present invention, the hysteresis loops of dry mixed samples that have been SPS compacted into dense magnets comprising different concentrations of solid-salt- matrix (SSM) synthesized SrFe^O particles and hydrothermal autoclave (AC) synthesized SrFe^O particles as described in Examples 2.2.1 and 2.3. The P_ prefix indicates that the samples are processed by SPS sintering. The sample P AC100 corresponds to a sample comprising 100% of hydrothermal autoclave (AC) synthesized SrFeisOig particles and displays the narrowest hysteresis opening and thereby lowest coercivity of the measured samples. The sample P SSM100 corresponds to a sample comprising 100% of solid-salt-matrix (SSM) synthesized SrFe^O particles and displays the widest hysteresis opening and thereby highest coercivity of the measured samples. P DM75, P DM50, and P DM25 corresponds to SPS-processed samples comprising 75 wt.%, 50 wt.% and 25 wt.% respectively of the AC SrFeisO particles, the remainder being SSM SrFeiaO particles. Extracted magnetic properties of the measured samples can be found in Table 6 of Example 3.

Figure 6: Hysteresis loops of a bulk magnet comprising misaligned domains according to the present invention, the hysteresis loops being of wet mixed samples that have been SPS compacted into dense magnets comprising different concentrations of solid- salt-matrix (SSM) synthesized SrFeisO particles and hydrothermal autoclave (AC) synthesized SrFeisO particles as described in Examples 2.2.2 and 2.3. The solid-salt- matrix (SSM) synthesized SrFeisO particles are added to the autoclave prior to hydrothermal autoclave synthesis. The same sample nomenclature is adapted as was used in Figure 5 above. Also in Figure 6, the P AC100 sample displays the narrowest hysteresis opening and the P SSM100 sample displays the wides hysteresis opening. Extracted magnetic properties of the measured samples can also be found in Table 6 of Example 3.

Figure 7: Hysteresis loops of a bulk magnet comprising misaligned domains according to the present invention, the hysteresis loops being of samples prepared by coldcompaction and subsequent calcination of a powder mixture comprised of 85 wt.% anisotropic goethite and 15 wt.% non-anisotropic SSM synthesized SrFeisO , referred to as 85% GO / 15% SSM. The samples are calcined at either 1 150 °C (large hysteresis opening, high coercivity) or 1250 °C (small hysteresis opening, low coercivity). Similar measurements have also been performed for other GO/SSM SrFeisOig ratios and for SLF/SSM SrFeisO samples following the same approach and elaborated in Examples 1 and 3. It is evident from Figure 7 that if the sample is calcined 1 150 °C, a magnet with a very high coercivity is produced, whereas increasing the calcination temperature only a little to 1250 °C has a detrimental effect on the coercivity which is drastically reduced, evident from the narrower hysteresis opening.

Figure 8: Schematic illustration of the measurement principle used for characterization of alignment and misalignment by 2D diffraction data. A randomly aligned sample will have full diffraction cones observable by the 2D detector, because in a randomly orientated sample there will always be some lattice planes that fulfill the Laue conditions that Q = H, where Q is scattering vector (Q = q_in-q_out, where qi_n and q_out is the incoming and outgoing wavevector, respectively) and H is the reciprocal lattice vector given by H=/?a*+kb*+/c*, where hkl is the Miller index and a*,b* and c* are the reciprocal unit cell vectors. Due to the preferred crystallographic alignment (or texture) of the crystallites the in the sample the Laue conditions are not always fulfilled for all 20 angles, causing the diffraction cones to be interrupted as seen schematically in Figure 8 (left). The diffraction cones are then azimuthally integrated into 5° slices and stacked as function of 20, as exemplified in Figure 8 (right). A model can now be build to refine the data and in order to describe the azimuthally caked data it is necessary to introduce partial alignment (or texture) in the structural refinements.

Figure 9: Zoom on azimuthally integrated data as described in Example 3.3.1. The samples have been prepared by compacting loose powders of: A) spherical hematite (a- FesOs, diameter ~ 100 nm) with strontium carbonate (SrCOs); B) spherical hematite (a- FesOs diameter ~100nm) and anisotropic goethite (a-FeOOH, needle shaped crystallites -100 nm long and 5 nm thick) with strontium carbonate (SrCOs); and C): anisotropic goethite (a-FeOOH, needle shaped crystallites -100 nm long and 5 nm thick) with strontium carbonate (SrCOs).

Figure 10: An example of a Electron Backscatter Diffraction (EBSD) SEM image of the surface of a spark plasma sintered sample made from SrFeisO prepared by autoclave synthesis. A) EBSD technique can detect the alignment of each crystalline grain domain located at the surface of a sample by measuring the diffraction angle relative to the incident incoming beam after a scattering event in with the sample. It is apparent by the uniformly distributed contrast of the mapped image, that a high percentage of the crystal grain domains are aligned confirming the high degree of grain alignment induced by the disclosed preparation process. If the image was mapped in color, a red color would be uniformly distributed across the image, while non-aligned gains would appear in a different color depending on the degree of misalignment. B) inverse pole figure revealing the vast majority of crystallites are aligned along the (00/) direction, i.e. the easy axis of the system.

Detailed description

One aspect of the present invention relates to a method for manufacturing a bulk magnetic material of hexaferrite, the bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, the method comprising the steps: a. Providing a first iron-based oxide comprising anisotropic crystallites, the anisotropic crystallites characterized by an average aspect ratio A/C is 5 to 500; b. Providing a second iron-based oxide comprising crystallites, the crystallites characterized by an average aspect ratio A/C < 3; c. Providing an amount of an alkaline earth metal (aem) precursor; d. Mixing said first and said second iron-based oxides with said alkaline earth metal (aem) precursor to obtain a final precursor mixture; e. Compacting said final precursor mixture by the application of uniaxial pressure of 200 MPa of 5000 MPa, thereby inducing alignment of the first iron-based precursor while the second iron-based precursor is not aligned by this step, to obtain a partially aligned precursor; f. Heating said partially aligned precursor, at a heating rate ranging from 10 °C/h to 10 °C/s, to a temperature ranging from 1000 °C to 1250 °C, to convert said partially aligned precursor into said bulk magnetic material of hexaferrite; and g. Isolating the thus formed bulk magnetic material of hexaferrite comprising an aligned magnetic part and a non-aligned magnetic part from the reaction mixture.

In one embodiment of the present disclosure, the hexaferrite manufactured by the described method is selected from the group consisting of M-type hexaferrite, X-type hexaferrite, and W-type hexaferrite, preferably M-type hexaferrite. Even further, in one embodiment of the present disclosure, the M-type hexaferrite is selected from the group consisting of M-type strontium hexaferrite (SrFeisO ), M-type barium hexaferrite (BaFeiaO ), M-type calcium hexaferrite (CaFeisO ) and substituents thereof, but is preferably M-type strontium hexaferrite (SrFeisOw).

The chemical and atomic structures of all of M-type, W-type and X-type hexaferrites are well-known to a person skilled in the art without further explanation. It is preferred in one embodiment each of the aligned and non-aligned parts of the bulk magnetic material comprises M-type strontium hexaferrite (SrFeisO ), such as consists of M- type strontium hexaferrite (SrFeisO ).

Aspect ratio: By this is understood the ratio between the length (A direction) of a crystal of the precursor and the height (C direction) of the same crystal (see also Figures 2a and 2b). This difference between A and C is what gives the precursor its unique properties in terms of facilitating alignment of the crystallites in the final magnet. Aspect ratio may be determined by standard methods known in the art, such as X-ray powder diffraction (XRD) or preferably by Transmission Electron Microscopy (TEM).

Anisotropic crystallite: By this is understood that the crystallites are not spherical, i.e., the crystallites are rather platelet, plate-like shaped, needle or needle-like shaped so that when compressed, a substantial fraction of the crystallites, such as all the crystallites will align in the same direction due to the difference in aspect ratio (see also Aspect ratio above).

The crystallite aspect ratio such as in relation to the first iron-based oxide material as disclosed herein is defined by an average A/C ratio, and should in one embodiment of the present disclosure be equal to or larger than 5 in order to be referred to as an anisotropic crystallite. The difference in aspect ratios between the first, and second iron-based oxides is crucial to the present disclosure, which relies on the preferred orientation of iron-based oxides having a large average A/C ratio compared to ironbased oxides with a low average A/C ratio, in the synthesis of hexaferrite permanent magnets with misaligned magnetic moments, preferably strontium hexaferrite permanent magnets.

In one embodiment, the first iron-based oxide is characterized by an average aspect ratio A/C is 5 to 500. In one embodiment, the average aspect ratio A/C of the first ironbased oxide is from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100, such as from 100 to 125, such as from 125 to 150, such as from 150 to 200, such as from 200 to 400, such as from 400 to 500

In one embodiment of the present disclosure, the first iron-based oxide is characterized by an average aspect ratio A/C is 5 to 100. In one embodiment, the average aspect ratio A/C of the first iron-based oxide is from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100.

In one embodiment of the present disclosure, the first iron-based oxide is characterized by an average aspect ratio A/C is 5 to 50, such as from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50.

In one embodiment, the second iron-based oxide is characterized by an average aspect ratio A/C < 3. In one embodiment, the average aspect ratio A/C of the second iron-based oxide is from 3.0 to 1 .0, such as from 3.0 to 2.5, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

In one embodiment, the average aspect ratio A/C of the second iron-based oxide is less than 3.0, such as less than 2.8, such as less than 2.7, such as less than 2.6, such as from 2.5 to 1 .0, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

In one embodiment, the average aspect ratio A/C of the second iron-based oxide is not equal to 3.0 or more.

In one embodiment of the present disclosure, the first iron-based oxide comprises anisotropic crystallites having a platelet, or platelet-like morphology.

In one embodiment of the present disclosure, the first iron-based oxide comprises anisotropic crystallites having a needle, or needle-like morphology.

Much like a deck of playing cards, when dropped on the floor, most of the cards will lay flat on top of each other, while only very few can be expected to land on their narrow side (the case for the platelet-like anisotropic crystallites). Likewise for needles, if needles are dropped to the floor the long part of the needle will lay flat parallel with the floor, while it is very unlikely that the needle will be standing up vertically (the case for the needle-like anisotropic crystallites).

To have predominantly all the crystallites in a magnetic sample aligned in the same direction is also to have the magnet moments of said sample aligned in the same direction. Figuratively speaking, this is equal to aligning all the magnetic field lines of small individual magnets in the same direction to achieve a synergistic effect and generate a larger unidirectional magnetic field. Thus magnets constructed in this way may possess superior magnetic properties compared to non-aligned versions of the same magnets, as evidenced in Examples 5, 6 and 8. The standard of evaluating magnetic properties in materials is to examine the hysteretic behaviour of a magnet (see Figure 1 ). Key parameters that govern the macroscopic magnetic properties of materials are remanence magnetization (/W_r), saturation magnetization (/W_s), coercive field (H_c), and maximum energy product (BH)max, all of which can be extracted from the magnetic hysteresis loop. For some applications such as electric motors, coercive field (H_c) is however generally viewed as being of major importance.

When measuring magnetic hysteresis, a sample is subjected to an external magnetic field, which is increased from zero and up. The magnetization of the sample will then grow as the external magnetic field is increased. When the magnetization of the sample no longer increases, despite the application of larger magnetic fields, the magnetization is said to have saturated. This value is called saturation magnetization (/W_s). The external magnetic field is then decreased back down to zero to demagnetize the sample. This causes the magnetization to decrease to a certain extent. At zero applied field (i.e., H = 0) if the magnetization is non-zero, this value will be equivalent to the remanence magnetization (/W_r). The sign of the external field is changed, and the field is increased, figuratively speaking, in the opposite direction. Since the magnetization at zero applied field of a magnet is non-zero, a negative field must be applied to bring the magnetization to zero. The value of this field is called the coercive field (H_c).

The alignment of moments in a sample will also impact the shape of the magnetic hysteresis curve as evidenced in Figure 1 . A highly aligned magnet will have a very square hysteresis curve where magnetization and demagnetization events occur very abruptly upon reaching the coercive field value. If the sample is less aligned, the hysteresis loop will be more smooth in its shape. Likewise the magnetization and demagnetization events will be more gradual.

The larger the crystallite aspect ratio of the precursor of the present disclosure (see Figures 2A and 2B), the higher is the probability for the crystallites to stack in a preferred orientation, which in turn facilitates improved magnetic properties.

Following the above analogy, the crystallites of the second iron-based oxide, characterized by an average aspect ratio A/C < 3 can be thought of as approximately spherical and/or isotropic crystallites which are not largely influenced by the arrangement of their surroundings. As such, a mixture of playing cards and spheres dropped to the floor will still result in most, if not all of the playing cards landing flat on the ground or on top or below the spheres. Some may be found at an angle around the spheres, however predominantly with the flat face aligned with the floor. If the spheres are thought of as having a certain magnetic moment, and the playing cards thought of as having another magnetic moment, then a situation arises wherein the magnetic moments of the playing cards are aligned uniformly in the same direction, while the magnetic moments of the spheres are randomly oriented.

In one embodiment of the present disclosure, the anisotropic crystallites of the first iron-based oxide is characterized by C ranging from 2 nm to 200 nm, such as from 2 nm to 10 nm, such as from 10 nm to 15 nm, such as from 15 nm to 20 nm, such as from 20 nm to 30 nm, such as from 30 nm to 50 nm, such as from 50 nm to 80 nm, such as from 80 nm to 110 nm, such as from 110 nm to 140 nm, such as from 140 nm to 170 nm, such as from 170 nm to 200 nm.

In one embodiment of the present disclosure, the anisotropic crystallites of the first iron-based oxide is characterized by A is ranging from 10 - 1000 nm, such as from 10 nm to 20 nm, such as from 20 nm to 30 nm, such as from 30 nm to 40 nm, such as from 40 nm to 50 nm, such as from 50 nm to 75 nm, such as from 75 nm to 100 nm, such as from 100 nm to 125 nm, such as from 125 nm to 250 nm, such as from 250 nm to 500 nm, such as from 500 nm to 1000 nm.

In one embodiment of the present disclosure, the first iron-based oxide is selected from the group consisting of goethite, hematite, six-line ferrihydrite, and hexaferrites, such as M-type hexaferrites, preferably M-type strontium hexaferrite (SrFeisO ) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrites and X-type hexaferrites.

In one embodiment of the present disclosure, the first iron-based oxide is a ferromagnetically interacting iron-based oxide, such as an iron-based oxide that is ferromagnetic at ambient conditions. In one embodiment of the present disclosure, the first iron-based oxide is a non- ferromagnetically interacting iron-based oxide, such as an iron-based oxide that is nonferromagnetic at ambient conditions.

Non-ferromagnetic: By this is understood a chemical entity having unpaired electrons, and where no permanent magnetism is observed (i.e., the magnetization is approximately zero under zero applied external field) within the temperature range relevant for the present disclosure, preferably at room temperature. The phrases “nonferromagnetic”, “non-ferromagnetically interacting”, and “non-magnetic” may be used interchangeably herein. By the same logic, “ferromagnetic”, “magnetic” and “ferromagnetically interacting” may be used interchangeably herein and refer to chemical entities having a non-zero magnetization under zero applied external field.

In one embodiment of the present disclosure, the first iron-based oxide is non- ferromagnetically interacting and is selected from goethite, hematite or six-line ferrihydrite, preferably goethite.

In one embodiment of the present disclosure, the first iron-based oxide is ferromagnetic and is selected from M-type hexaferrite, such as M-type strontium hexaferrite (SrFeisOig) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrite or X-type hexaferrite.

The first iron-based oxide, which comprises a large fraction of crystallites having a platelet or needle morphology defined by an average A/C aspect ratio larger than 5, can be transformed into a hexaferrite permanent magnet, either in a one-step process by way of spark plasma sintering (SPS) or in a two-step process by first compacting a crystalline powder into a pellet by application of uniaxial pressure and subsequently calcination at temperatures between 1000 °C and 1250 °C.

When the first iron-based oxide is non-ferromagnetic, the anisotropic crystallites of the first iron-based oxide can be aligned in a preferred orientation solely by the application of pressure and a permanent magnetic material can subsequently be produced by calcination of the pressed partially aligned precursor. When the first iron-based oxide however is ferromagnetic in nature, magnetic interaction between individual anisotropic crystallites figuratively speaking “locks” the crystallites in place and prevents alignment using pressure alone. In such situations, it is necessary to either apply a large external magnetic field or to heat the sample above the Curie temperature of the ferromagnetic crystallites to break the magnetic interaction. The most efficient approach to this is spark plasma sintering (SPS) where compaction and heating (sintering) can be accomplished in one step.

In one embodiment of the present disclosure, the method steps of compacting and heating as described herein may be performed sequentially by a first step of cold compaction and a second step of calcination, or the steps may be performed simultaneously such as by spark plasma sintering (SPS)

In one embodiment of the present disclosure, the second iron-based oxide is selected from the group consisting of M-type strontium hexaferrite (SrFeisO ), hematite, M-type barium hexaferrite (BaFeisO ), M-type calcium hexaferrite (CaFeisO ), goethite, W- type hexaferrites and X-type hexaferrites.

In one embodiment of the present disclosure, the average aspect ratio A/C of the second iron-based oxide is from 3.0 to 1 .0, such as from 3.0 to 2.5, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

In one embodiment of the present disclosure, the first iron-based oxide and the second iron-based oxide are mixed in a ratio ranging from 99:1 by weight to 50:50 by weight.

In one embodiment of the present disclosure, the mixing ratio of the first iron-based oxide and the second iron-based oxide ranges from 99:1 to 50:50 by weight, such as from 99:1 to 95:5, such as from 95:5 to 90:10, such as from 90:10 to 85:15, such as from 85:15 to 80:20, such as from 80:20 to 75:25, such as from 75:25 to 70:30, such as from 70:30 to 65:35, such as from 65:35 to 60:40, such as from 60:40 to 55:45, such as from 55:45 to 50:50. In one embodiment of the present disclosure, the first iron-based oxide is goethite, and the second iron-based oxide is strontium hexaferrite.

In one embodiment of the present disclosure, the first iron-based oxide is goethite, and the second iron-based oxide is strontium hexaferrite, and the mixing ratio of the first iron-based oxide and the second iron-based oxide is from 90:10 to 70:30 by weight, such as from 85:15 to 75:25 by weight, such as 80:20 by weight.

In one embodiment of the present disclosure, the first iron-based oxide is goethite, and the second iron-based oxide is hematite.

In one embodiment of the present disclosure, the first iron-based oxide is goethite, and the second iron-based oxide is hematite, and the mixing ratio of the first iron-based oxide and the second iron-based oxide is from 90:10 to 70:30 by weight, such as from 85:15 to 75:25 by weight, such as 80:20 by weight.

In one embodiment of the present disclosure, the first iron-based oxide is six-line ferrihydrite, and the second iron-based oxide is strontium hexaferrite.

In one embodiment of the present disclosure, the first iron-based oxide is six-line ferrihydrite, and the second iron-based oxide is strontium hexaferrite, and the mixing ratio of the first iron-based oxide and the second iron-based oxide is from 90:10 to 70:30 by weight, such as from 85:15 to 75:25 by weight, such as 80:20 by weight.

In one embodiment of the present disclosure, the first iron-based oxide is six-line ferrihydrite, and the second iron-based oxide is hematite.

In one embodiment of the present disclosure, the first iron-based oxide is six-line ferrihydrite, and the second iron-based oxide is hematite, and the mixing ratio of the first iron-based oxide and the second iron-based oxide is from 90:10 to 70:30 by weight, such as from 85:15 to 75:25 by weight, such as 80:20 by weight.

In one embodiment of the present disclosure, the alkaline earth metal (aem) precursor is provided in an amount to obtain a Fe/aem molar ratio ranging from 8 to 14, such as from 8 to 9, such as from 9 to 10, such as from 10 to 10.5, such as from 10.5 to 1 1 such as from 11 to 11 .5, such as from 1 1 .5 to 12, such as from 12 to 13, such as from 13 to 14.

In one embodiment of the present disclosure, the alkaline earth metal (aem) precursor comprises an alkaline earth metal selected from the group consisting of Sr, Ba, Ca, Mg, Be and Ra, preferably comprises Sr or Ba or Ca, most preferably Sr.

In one embodiment of the present disclosure, the alkaline earth metal (aem) precursor comprises Sr, and is selected as one or more from the group consisting of SrCO₃, SrO, Sr(OH)₂, SrCI₂, Sr(NO₃)₂, SrSC , Sr(OAc)2, Sr₃(PC>4)2, and hydrates thereof, preferably SrCO₃.

In one embodiment of the present disclosure, the alkaline earth metal (aem) precursor comprises Ba, and is selected as one or more from the group consisting of BaCO₃, BaO, Ba(OH)₂, BaCI₂, Ba(NO₃)₂, BaSC , Ba(OAc)₂, Ba₃(PC>4)2, and hydrates thereof, preferably BaCO₃.

In one embodiment of the present disclosure, the alkaline earth metal (aem) precursor comprises Ca, and is selected as one or more from the group consisting of CaCO₃, CaO, Ca(OH)₂, CaCI₂, Ca(NO₃)₂, CaSC , Ca(OAc)₂, Ca₃(PC>4)2, and hydrates thereof, preferably CaCO₃.

In one embodiment of the present disclosure, the applied uniaxial pressure is from 200 MPa to 5000 MPa, such as from 200 MPa to 500 MPa, such as from 500 MPa to 650 MPa, such as from 650 MPa to 800 MPa, such as from 800 MPa to 1000 MPa, such as from 1000 MPa to 1200 MPa, such as from 1200 MPa to 1500 MPa, such as from 1500 MPa to 2000 MPa, such as from 2000 MPa to 3000 MPa, such as from 3000 MPa to 4000 MPa, such as from 4000 MPa to 5000 MPa, preferably the applied uniaxial pressure is from 800 MPa to 1500 MPa, such as 800 MPa to 1000 MPa, such as from 1000 MPa to 1200 MPa, such as from 1200 MPa to 1500 MPa.

In one embodiment of the present disclosure, the applied uniaxial pressure is from 800 MPa to 1200 MPa, preferably from 1000 MPa to 1200 MPa. In one embodiment of the present disclosure, the temperature is from 1000 °C to 1250 °C, such as from 1050 °C to 1075 °C, such as from 1075 °C to 1100 °C, such as from

1100 °C to 1125 °C, such as from 1125 °C to 1150 °C, such as from 1150 °C to 1175

°C, such as from 1175 °C to 1200 °C, such as from 1200 °C to 1220 °C, such as from

1220 °C to 1240 °C, such as from 1240 °C to 1250 °C.

In one embodiment of the present disclosure, the temperature is from 1000 °C to 1240 °C, such as from 1075 °C to 1240 °C, such as from 1100 °C to 1200 °C.

In one embodiment of the present disclosure, the heating rate is from 10 °C/h to 10 °C/min, such as from 10 °C/h to 30°C/h, such as from 30 °C/h to 45 °C/h, such as from 45 °C/h to 1 °C/min, such as from 1 °C/min to 2 °C/min, such as from 2 °C/min to 5 °C/min, such as from 5 °C/min to 10 °C/min, preferably 5 °C/min.

In one embodiment of the present disclosure, the heating rate is from 10 °C/h to 10 °C/sec, such as from 10 °C/h to 30°C/h, such as from 30 °C/h to 45 °C/h, such as from 45 °C/h to 1 °C/min, such as from 1 °C/min to 2 °C/min, such as from 2 °C/min to 5 °C/min, such as from 5 °C/min to 10 °C/min, such as from 10 °C/min to 30 °C/min, such as from 30 °C/min to 1 °C/sec, such as from 1 °C/sec to 5 °C/sec, such as from 5 °C/sec to 10 °C/sec.

Another aspect of the present invention relates to a bulk magnetic material obtainable by the method as described herein above

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is comprising an aligned magnetic part and a non-aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites.

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is characterized in that the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is further characterized by a coercivity ranging from 300 kA/m to 1000 kA/m.

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is characterized in that the aligned magnetic part constitutes 50 wt.% to 99 wt.% of the bulk part of the magnetic material.

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is characterized in that the non-aligned magnetic part constitutes 1 wt.% to 50 wt.% of the bulk part of the magnetic material.

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is characterized in that the aligned, and non- aligned magnetic part of hexaferrite is M-type strontium hexaferrite (SrFeisO ).

In one embodiment of the present disclosure, the bulk magnetic material obtainable by the method as described herein above is characterized by not containing rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y), including oxides or salts of rare-earth metals.

Another aspect of the present invention relates to a bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites; wherein the aligned magnetic part is uniformly aligned, and wherein the non-aligned magnetic part is not aligned, neither uniformly, nor with respect to the aligned magnetic part. Aligned and non-aligned parts. By this is understood the alignment of the magnetic moment of each individual magnetic part, both with respect to each other but also with respect to the surface normal of the bulk magnetic material of the invention.

“Alignment” and “texture” may be used interchangeably herein. Because the orientation of the magnetic moment is related to the spatial orientation of the crystallites, alignment may also refer to crystallite alignment indirectly.

As a consequence of the anisotropic nature of the crystallites comprised in the first iron-based oxide, during production of the bulk magnetic material, the crystallites and therefore also magnetic moments of the first iron-based oxide will preferentially align in a uniform direction, and the magnetic moments preferentially coinciding with the surface normal of the bulk magnetic material of the present invention, thereby constituting an aligned magnetic part within the meaning of the present invention. By the same logic, the crystallites of the second iron-based oxide described herein which are characterized by a low aspect ratio (average aspect ratio A/C less than 3) will not align because the anisotropy of the crystallites is not sufficient to achieve this, i.e., the crystallites are non-anisotropic. Therefore both the crystallites and magnetic moments comprised in the second iron-based oxide are randomly oriented with respect to both the magnetic easy axis of the bulk magnetic material of the invention, but optionally also with respect to the surface normal of the same bulk magnetic material, thereby constituting a non-aligned magnetic part.

As used herein, the phrase “magnetic easy axis” is to be construed as a direction in space along which an anisotropic magnetic material is energetically favourable to magnetize. In other words, the magnetic easy axis is an energetically favourable direction of spontaneous magnetization in a magnetically anisotropic material. For comparison, magnetically isotropic materials have no easy axis because all directions are equally favourable to magnetize, the phrase is well known to persons skilled in the field.

As used herein, the phrase “surface normal” is to be construed as a vector which is perpendicular to the surface at a given point. The phrase is well known to persons skilled in the field. In one embodiment of the present disclosure, the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis of the bulk magnetic material.

In one embodiment of the present disclosure, the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis of the bulk magnetic material.

In one embodiment of the present disclosure, the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the surface normal of the bulk magnetic material.

In one embodiment of the present disclosure, the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

In one embodiment of the present disclosure, the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, such as within ±24°, such as within ±23°, such as within ±22°, such as within ±21 °, such as within ±20°, such as within ±19°, such as within ±18°, such as within

±17°, such as within ±16°, such as within ±15°, such as within ±14°, such as within

±13°, such as within ±12°, such as within ±11 °, such as within ±10°, such as within ±9°, such as within ±8°, such as within ±7°, such as within ±6°, such as within ±5°.

In one embodiment, the magnetic easy axis of the aligned magnetic part coincides within ±20° of the surface normal of the bulk magnetic material, and wherein the non- aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

In one embodiment, the magnetic easy axis of the aligned magnetic part coincides within ±15° of the surface normal of the bulk magnetic material, and wherein the non- aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

In one embodiment, the magnetic easy axis of the aligned magnetic part coincides within ±10° of the surface normal of the bulk magnetic material, and wherein the non- aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

In one embodiment, the magnetic easy axis of the aligned magnetic part coincides within ±5° of the surface normal of the bulk magnetic material, and wherein the non- aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

In one embodiment of the present disclosure, the degree of texture and alignment as well as the composition distribution of aligned, and non-aligned parts (or phases) in the bulk magnetic material may be determined by diffraction methods known to persons skilled in the art. In one embodiment, such a diffraction method may be 2D X-ray diffraction. In another embodiment, such a diffraction method may be Electron- Backscatter Diffraction (EBSD). EBSD may be performed in accordance with ISO 2417:2009.

From the collected 2D diffraction data a two phase model is used to take account of the aligned and non-aligned parts. Both phases are exemplary fixed as M-type strontium hexaferrite (SrFeiaO ) and the unit cell and atomic position is fixed for the two phases. The difference between the two phases should be the alignment, sometimes referred to as texture - phase 1 , which is based on the anisotropic platelet or needle crystallites is textured, while phase 2, which is based on the spherical or non-anisotropic crystallites is non-textured. The refinement of the measured data returns a phase fraction of the two phases. The obtained phase fraction will correlate to the amount of first iron-based oxide and second iron-based oxide used in the production process respectively, (e.g., anisotropic goethite and spherical hematite). Phase 1 should give the weight fraction of goethite ±5 wt.%, while the non-textured sample should be equal to the amount of spherical hematite used ±5 wt.%. In an example where 15 wt.% spherical hematite is added to anisotropic goethite, the weight fraction of the unaligned phase should be I Q- 20 wt.%; if 25 wt.% of spherical hematite is added instead, the obtained weight fraction of the unaligned phase should be 20-30 wt.% and so forth.

In one embodiment of the present disclosure, the aligned, and non-aligned magnetic part of hexaferrite are individually selected from the group consisting of M-type hexaferrite, such as M-type strontium hexaferrite (SrFeisO ) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrite and X-type hexaferrite. In one embodiment, the aligned, and non-aligned magnetic part of hexaferrite is M-type strontium hexaferrite (SrFeisO ).

In one embodiment of the present disclosure, the aligned magnetic part constitutes 50 wt.% to 99 wt.% of the bulk magnetic material, such as from 50 wt% to 60 wt.%, such as from 60 wt% to 70 wt.%, such as from 70 wt% to 75 wt.%, such as from 75 wt% to 80 wt.%, such as from 80 wt% to 85 wt.%, such as from 85 wt% to 90 wt.%, such as from 90 wt% to 95 wt.%, such as from 95 wt% to 99 wt%.

In one embodiment of the present disclosure, the aligned magnetic part constitutes 70 wt.% to 90 wt.%.

In one embodiment of the present disclosure, the aligned magnetic part constitutes 75 wt.% to 85 wt.%.

In one embodiment of the present disclosure, the aligned magnetic part constitutes 80 wt.% to 90 wt.%.

In one embodiment of the present disclosure, the non-aligned magnetic part constitutes 1 wt.% to 50 wt.% of the bulk magnetic material, such as from 1 wt.% to 5 wt.%, such as from 5 wt.% to 10 wt.%, such as from 10 wt.% to 15 wt.%, such as from 15 wt.% to 20 wt.%, such as from 20 wt.% to 25 wt.%, such as from 25 wt.% to 30 wt.%, such as from 30 wt.% to 40 wt.%, such as from 40 wt.% to 50 wt.%. In one embodiment of the present disclosure, the non-aligned magnetic part constitutes 15 wt.% to 25 wt.%.

In one embodiment of the present disclosure, the aligned magnetic part constitutes 10 wt.% to 20 wt.%.

In one embodiment of the present disclosure, the bulk magnetic material is further characterized by a coercivity ranging from 200 kA/m to 1000 kA/m, such as from 200 kA/m to 250 kA/m, such as from 250 kA/m to 300 kA/m, such as from 300 kA/m to 350 kA/m, such as from 350 kA/m to 375 kA/m, such as from 375 kA/m to 400 kA/m, such as from 400 kA/m to 425 kA/m, such as from 425 kA/m to 450 kA/m, such as from 450 kA/m to 500 kA/m, such as from 500 kA/m to 750 kA/m, such as from 750 kA/m to 1000 kA/m.

In one embodiment of the present disclosure, the bulk magnetic material is further characterized by a coercivity ranging from 300 kA/m to 1000 kA/m, such as from 300 kA/m to 350 kA/m, such as from 350 kA/m to 375 kA/m, such as from 375 kA/m to 400 kA/m, such as from 400 kA/m to 425 kA/m, such as from 425 kA/m to 450 kA/m, such as from 450 kA/m to 500 kA/m, such as from 500 kA/m to 750 kA/m, such as from 750 kA/m to 1000 kA/m.

In one embodiment of the present disclosure, the bulk magnetic material is further characterized by a coercivity ranging from 350 kA/m to 450 kA/m.

In one embodiment of the present disclosure, the aligned magnetic part is further characterized by an average aspect ratio A/C ranging from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100, such as from 100 to 125, such as from 125 to 150, such as from 150 to 200, such as from 200 to 400, such as from 400 to 500.

In one embodiment of the present disclosure, the non-aligned magnetic part is further characterized by an average aspect ratio A/C ranging from 3.0 to 1 .0, such as from 3.0 to 2.5, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

In one embodiment, the average aspect ratio A/C of the non-aligned magnetic part is less than 3.0, such as less than 2.8, such as less than 2.7, such as less than 2.6, such as from 2.5 to 1 .0, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

In one embodiment, the average aspect ratio A/C of the non-aligned magnetic part is not equal to 3.0 or more.

In one embodiment of the present disclosure, the aligned magnetic part and non- aligned magnetic part are magnetically coupled, such as in a two-phase coupled magnetic system.

In one embodiment of the present disclosure, the bulk magnetic material described herein does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y).

As a result of the enhanced magnetic properties obtained by the controlled misalignment of magnetic moments in the bulk magnetic material of the present invention, the present disclosure demonstrates a broad and useful potential in replacement of other ferrite materials or NIB rare-earth magnets.

Further aspects of the present invention relates generally to the bulk magnetic materials as described above herein or the bulk magnetic material obtained by the method as described above herein for use as magnetic component in devices.

In one embodiment, such a device may be an electric motor. Other possible devices known to persons skilled in the art may be (non-limiting) selected from the group consisting of storage devices, generators, audio devices, magnetic imaging scanners, magnetic brakes, linear motors, electrodynamic bearings, and magnetic toys. Examples

Example 1 : Preparation of partially misaligned SrFe^Oig hexaferrite magnets from a mixture of goethite nanoparticles and solid salt matrix (SSM) synthesized SrFe^Oig nanoparticles.

1.1 - Preparation of anisotropic goethite nanoparticles.

Rod like a-FeOOH nanocrystallites were synthesized by employing hydrothermal synthesis. A 40 ml solution of Fe(NO3)3-9H₂O with concentration 1 M was prepared and 20 ml of an 8.0 M solution of NaOH was added dropwise to the nitrate containing solution under constant magnetic stirring causing the transparent red solution to form a gel like compound. The amount of NaOH was adjusted to giving a 1 :4 ratio of Fe³⁺:OH^_. The precursor gel was allowed for stirring for one hour. The precursor gels were transferred to a 5 L polypropylene plastic bottle and placed inside an oven for 18 hours at 70°C.

1.1a - alternative preparation of anisotropic goethite nanoparticles.

Rod like a-FeOOH nanocrystallites were synthesized by employing hydrothermal synthesis. A 40 ml solution of Fe(NO3)3-9H₂O with concentration 1 M was prepared and 20 ml of an 8.0 M solution of NaOH was added dropwise to the nitrate containing solution under constant magnetic stirring causing the transparent red solution to form a gel like compound. The amount of NaOH was adjusted to giving a 1 :4 ratio of Fe³⁺:OH^_. The precursor gel was allowed for stirring for one hour. The precursor gels were transferred to a 5 L polypropylene plastic bottle and placed inside an oven for 18 hours at 70 °C. Particle sizes extracted from TEM analysis of the sample: A = 1 16 nm, C = 15 nm, A/C = 7.7

1.1 b -preparation of anisotropic hematite nanoparticles.

Rod like a-FeOOH nanocrystallites prepared according to 1 .1 a above were placed in an oven and heated at 350 °C for 30 minutes which initiates dehydration of the goethite and results in formation of anisotropic hematite nanocrystallites. Particle sizes extracted from TEM analysis of the sample: A = 116 nm, C = 15 nm (A/C = 7.7).

1.2 - Preparation of anisotropic six-line ferrihydrite (SLF) nanoparticles.

Six-line ferrihydrite (SLF) nanocrystallites were synthesized by employing a hydrothermal synthesis route. A 25 ml solution of 3.0 M Fe(NO3)3'9H₂O and 7 ml of a 0.75 M solution Sr(NOs)2 were prepared and 38 ml of an 8.0 M solution of NaOH (Technical grade, Sigma Aldrich, purity >98%) was added dropwise to the nitrate containing precursor solution under constant magnetic stirring causing the transparent solution to form a gel-like compound. The Fe/Sr ratio was fixed to be 8 and the [OH ] to [NO3 ] was kept at 1.29. Subsequently, the precursor gel was allowed stirring for approximately 3 hours. The precursor gels were then transferred to a 175 ml autoclave and placed inside an oven for 5 hours at 200 °C. Crystallite sizes extracted from X-ray powder diffraction: A = 16 nm, C = 5.2 nm (A/C = 3.1 ).

1.3 - Preparation of SrFe^Oig nanoparticles using NaCI solid-salt-matrix (SSM) synthesis.

The NaCI solid-salt-matrix (SSM) synthesized SrFe^O nanocrystallites were prepared by mixing 4.7 g SrCh SHsO dissolved in 17 ml distilled H2O with 55 g FeCh SHsO (Sigma Aldrich technical grade with purity >98%) dissolved in 100 ml distilled H2O. The [Fe³⁺]:[Sr²⁺] molar ratio used was 11.5:1 , which gives a Sr²⁺ excess compared with the stoichiometric ratio of 12:1. 32 ml of a 1 M solution of Na2COs (Chem-Solution GmbH, 99.98% purity) was subsequently added to the metal ion solution under constant stirring, with a [Na⁺]:[CI ] molar ratio equal to 1. Finally, 9 ml 5 M citric acid (>99% purity, Sigma Aldrich) was added and the solution was stirred until the mixture was completely homogeneous. The molar ratio between citric acid and Na2COs was 1 .5. The solution was dried in a convection oven at 120 °C overnight forming a porous gel. The gel was crushed in a mortar and placed in an approximately 2 mm thick layer in a convection oven for 1 hour at 450 °C, to burn off organic residues. Afterwards, the precursor was calcined for 1 hour at 790 °C and cooled to room temperature.

The product was washed and centrifuged once with 100 ml of a 4 M HNO3 and four times with distilled water to remove NaCI and potential SrCOs, which is formed due to excess of Sr²⁺. Finally, the SrFe^O powder was dried in a convection oven at 90 °C. Crystallite sizes extracted from X-ray powder diffraction: A = 60 nm, C = 25 nm (A/C = 2.4). Particle sizes extracted from TEM analysis of the sample: A = 62 nm, C = 28 nm (A/C = 2.2).

1.4 - Preparation of partially aligned goethite/SrFe^Oig SSM or hematite/SrFe^Oig SSM or SLF/SrFei20i9 SSM particle precursors for highly coercive SrFe^Oig magnets.

Goethite (GO) anisotropic nanoparticles according to Example 1.1 or 1.1 a or hematite anisotropic nanoparticles according to Example 1.1 b or six-line ferrihydrite (SLF) nanoparticles according to Example 1.2 were mixed with SSM synthesized SrFe^O particles of Example 1.3 so as to get a homogenous mixture. The proportions chosen were 100% 1 0%, 85% 1 15%, 80% 1 20% and 75% 1 25% by weight. The composition of each sample was analyzed with an X-ray fluorescence spectrometer. This was performed to determine the concentration of Sr²⁺ in the mixture. The ratio of Fe/Sr was adjusted to 10 by addition of SrCOs and confirmed by energy dispersive X-ray fluorescence spectroscopy using a NEX CG Rigaku spectrometer.

1.5 - Cold compaction and calcination of GO/SrFei2Oi9 SSM or hematite/SrFe^Oig SSM or SLF/SrFei20i9 SSM particles precursor for highly coercive SrFe^Oig magnets.

Compaction of the homogenous powder mixtures of Example 1 .4 into bulk magnets was done by conventional uniaxial pressing. Approximately 0.08 g mixture of either GO/SSM SrFeisOig or SLF/SSM SrFe^O was employed for the production of each pellet and loaded into a 6 mm die. A maximum of pressure of approximately 1 .2 GPa was applied for 5 min to each pellet. The powders from each proportion ratio specified under Example 1.4 were sintered at approximate temperatures of 1150°C, 1190°C and 1250°C for 30 min. The heating ramp used was 5°C/min and the samples were placed in a Carbolite tubular furnace.

Example 2: Preparation of partially misaligned SrFe12O19 hexaferrite magnets from a mixture of hydrothermal autoclave synthesized (AC) SrFe^Oig nanoparticles and solid salt matrix (SSM) synthesized SrFe^Oig nanoparticles.

2.1 - Synthesis of hydrothermal autoclave synthesized (AC) SrFeigOig.

SrFeisOig nanocrystallites were synthesized using 5 ml of a 1 .0 M Sr(NOs)2 and 30 ml of 1 .0 M a Fe(NO3)3'9H2O (>98% purity, Sigma Aldrich) dissolved in deionized water. The metal solutions were mixed in the [Fe³⁺]:[Sr²⁺] molar ratio was 6. Water was added and then the metal solution was mixed and 9.4 ml of 16 M NaOH was slowly added dropwise to the metal solution under constant magnetic stirring forming a homogeneous brown precipitate using a [OH ]:[NO3-] molar ratio of 1.5. The Sr²⁺ concentration in the final precursor was 0.1 M. The precipitate was prepared directly in a Teflon-lined steel autoclave with a volume of 170 ml. The autoclave was placed in a preheated Carbolite convection box furnace set at 240 °C for three hours. Hereafter, the autoclave was cooled to room temperature and the product was washed with 20 ml of a 4 M HNO3, and subsequently washed three times in deionized water and dried at 90 °C. Particle sizes extracted from TEM analysis of the sample: A = 260 nm, C = 32 nm (A/C = 8.2).

2.2 - Mixing of powders.

SSM synthesized SrFeisO nanoparticle powders were prepared as described above under Example 1 .2. The AC and SSM synthesized crystallites were mixed in two different ways: A) Dry mixing: the crystallites were dry mixed by hand using pestle and mortar. B) Wet mixing: the as-prepared SSM powder was added to the autoclave precipitate.

2.2.1 - Dry mixing.

Three different mass ratios between AC and SSM were prepared (AC:SSM 75:25, 50:50, and 25:75). For each mixture, a total of 0.6 g powder was used. The sample names are DM75, DM50, and DM25 depending on the amount of AC prepared powder in the sample (75 wt.% AC for the DM75 sample etc.).

2.2.2 - Wet mixing.

The as-prepared SSM powder was added to the autoclave. The Fe³⁺ and Sr²⁺ solution for all samples were made in one batch and divided to into three Teflon lined steel autoclaves. NaOH was added to the individual autoclaves. The SSM prepared powder was then added to the autoclave inserts and mixed with the precipitate using a glass spatula. Notably magnetic stirring cannot be used as the SSM crystallites are highly magnetic. Three samples were made with the ratios AC:SSM ratios 75:25, 50:50 or 25:75 calculated from the theoretical AC synthesis yield, assuming 100% yield with respect to the Fe³⁺ content. The samples are named WM75, WM50, and WM25 according to the theoretical amount of AC prepared powder in the sample (75 wt.% AC for the WM75 sample etc.).

2.3 - Spark plasma sintering (SPS) of mixed AC/SSM powders.

The powder samples described under Example 2.2.1 and 2.2.2 were compacted into dense pellets using a Spark Plasma Sintering (SPS) press (SPS Syntex Inc., Dr. Sinter Lab™ series). Approximately 0.45 g powder were loaded into a graphite matrix of 8 mm inner diameter and sintered at 950 °C for 5 minutes at 100 MPa. The resulting pellets have a typical thickness of ~1 .2 mm, and are denoted in the sample naming by a P_ prefix to indicate processing by SPS.

Example 3: Characterization of partially misaligned SrFe12O19 hexaferrite magnets.

3.1 - Transmission electron microscopy

Transmission electron microscopy (TEM) were recorded on FEI TALOS F200 (200V) (S) TEM microscope. A representative TEM image of the goethite nanoparticles of Example

1.1 are shown in Figure 4A, while a representative TEM image of the SSM SrFeisO nanoparticles is shown in Figure 4B.

3.2 - Magnetic Properties

A Physical Property Measurement System (PPMS) from Quantum Design, equipped with a Vibrating Sample Magnetometer (VSM) was used for assessing the magnetic properties of the powders as well as the pellets. Cylindrical near-zero background brass holders were used together with quartz rods to hold the sample in place during the measurement. Hysteresis curves were measured at 300 K in an external applied magnetic field cycled between ±3 T. The frequency was set at 40 Hz and the field sweep rate was set at 50 Oe/s. The saturation magnetization, M_s, was determined based on the law of approach to saturation.

Magnetic hysteresis loops of the permanent magnets produced by cold compaction and subsequent calcination of goethite/SSM SrFeiaO (referred to as GO/SSM) in 85:15 ratio by weight can be found in Figure 7. Hysteresis loops have also been measured for other weight ratios and mixtures as illustrated by the extracted magnetic parameters found in Tables 1 -4 here below, but their hysteresis loops would be redundant to include at this point.

Table 1 - magnetic properties extracted from hysteresis loops of the 85% GO / 15% SSM sample produced by cold compaction and subsequent calcination

Table 2 - magnetic properties extracted from hysteresis loops of the 75% GO /25%> SSM sample produced by cold compaction and subsequent calcination Table 3 - magnetic properties extracted from hysteresis loops of the 85%> SLF / 15%> SSM sample produced by cold compaction and subsequent calcination

Table 4 - magnetic properties extracted from hysteresis loops of the 75%> SLF/ 25% SSM sample produced by cold compaction and subsequent calcination

For the hematite/SrFeisO SSM (80% 120%) sample, the following parameters are extracted: M_s = 78.4 Am²/kg, M M_S = 0.65, H_c = 411 kA/m, and (BH)_max = 18 kJ/m³, also indicating that this approach results in high-coercivity magnets with H_c above 400 kA/m. Without wishing to be bound by theory, the inventors contemplate the main reason behind the large opening of the hysteresis observed generally and exemplified in the case of GO/SSM mixed particles as possibly being attributed due to the fact that there are pinning sites available for the largely coercive SSM SrFeisO particles. In the case of 85 wt.% GO/15 wt.% SSM particles, the hysteresis is observed to be expanded with a high coercivity of 404 kA/m, which may be attributed dispersed pinning sites in the SrFeisOig matrix. The same phenomenon is observed in the case of 75% GO/25% SSM particles. For reference, magnetic properties extracted from a hysteresis loop measured of an SrFeisOig permanent magnet sample obtained by cold-compaction and calcination of a mixture of goethite and strontium carbonate; a sample that does not comprise a significant degree of misalignment, is below in Table 5

Table 5 - magnetic properties extracted from hysteresis loops of the 100% GO sample produced by cold compaction and subsequent calcination of a mixture of goethite anisotropic needles and strontium carbonate.

As it can be concluded from the comparison between Tables 1 -4 and 5, the introduction of misaligned magnetic moments results in a significant increase in coercivity of the resulting permanent strontium hexaferrite magnet.

For the AC/SSM SrFeisOig samples, hysteresis loops can be found in Figures 5 and 6, for the dry mixed and wet mixed SPS-processed samples respectively. Extracted magnetic parameters are found here below in Table 6.

Table 6 - magnetic properties extracted from hysteresis loops of the AC/SSM samples comprising varying amounts of hydrothermal autoclave synthesized SrFe^O , and solid-salt-matrix synthesized SrPe^O . The samples are compacted and sintered in one step using SPS processing as described herein.

It can be noted that the cold-compacted and subsequently calcined samples show comparable and larger coercivity compared to the SPS-processed samples. On key advantage of using cold-compaction and calcination rather than SPS processing is the scalability, and the former allows to mass produce permanent magnets using this approach at a reduced cost.

3.3 - Diffraction data

3.3.1 - Characterization of misaligned permanent magnets of SrFe^Oig by 2D diffraction data

The sample is aligned with the surface normal being rotated 45° with respect to the incoming beam (co = 45°). Figure 8 schematically shows the measurement principle used for characterization of misalignment by 2D diffraction data. A randomly aligned sample will have full diffraction cones observable by the 2D detector, because in a randomly orientated sample there will always be some lattice planes that fulfill the Laue conditions that Q = H, where Q is scattering vector (Q = q_in-q_out, where qi_n and q_out is the incoming and outgoing wavevector, respectively) and H is the reciprocal lattice vector given by H=/?a*+kb*-i-/c*, where hkl is the Miller index and a*,b* and c* are the reciprocal unit cell vectors. Due to the preferred crystallographic alignment (or texture) of the crystallites the in the sample the Laue conditions are not always fulfilled causing the diffraction cones to be interrupted as seen schematically in Figure 8 (left). The diffraction cones are then azimuthally integrated into 5° slices and stacked as function of 20, as exemplified in Figure 8 (right). A model can now be build to refine the data and in order to describe the azimuthally caked data it is necessary to introduce partial alignment (or texture) in the refined model.

In Figure 9 is shown a zoom on azimuthally integrated data collected using synchrotron radiation (Petra-Ill, Germany, beamline P02.1 using a 60 keV X-ray beam). The investigated samples of SrFeiaO were prepared by compacting loose powders of:

A) spherical hematite (a-FesOs, diameter ~ 100 nm) and strontium carbonate (SrCOs);

B) anisotropic goethite (a-FeOOH, needle shaped crystallites -100 nm long and 5 nm thick) with strontium carbonate (SrCOs) and spherical hematite (a-FesOs diameter ~100nm);

C) anisotropic goethite (a-FeOOH, needle shaped crystallites -100 nm long and 5 nm thick) and strontium carbonate (SrCOs).

For all samples, the powders are mixed in a mortar by grinding for 15 min, and subsequently poured into a pressing matrix, which is cold compacted at a pressure of maximum 1.2 GPa for 5 min. The obtained pellets have subsequently been sintered at 1200 °C. The samples are rotated 45° with respect to the incoming X-ray beam and the diffraction signal is collected on a 2D detector.

By exploiting the difference in morphology it is possible to make a non-aligned sample by using only crystallites with spherical (or isotropic) morphology. Using only needle- or platelet-shaped crystallites it is possible to make a highly textured sample. By mixing spherical and needle/platelet shaped crystallites it is possible to introduce misalignment constituents into the aligned matrix. Figure 9B shows the azimuthally integration of a sample with misaligned constituents in the matrix.

3.3.2 - Evaluating the degree of texture based on 2D diffraction data:

To model the data a two phase model is used to take account of the aligned and non- aligned parts. Both phases are fixed as M-type strontium hexaferrite (SrFeisO ) and the unit cell and atomic position is fixed for the two phases. The difference between the two phases should be the alignment, sometimes referred to as texture - phase 1 , which is based on the anisotropic platelet or needle crystallites is textured, while phase 2, which is based on the spherical or non-anisotropic crystallites is non-textured. The refinement of the measured data returns a phase fraction of the two phases. The obtained phase fraction will correspond to the amount of first iron-based oxide and second iron-based oxide used in the production process respectively, (e.g., anisotropic goethite and spherical hematite). Phase 1 should give the weight fraction of goethite ±5 wt.%, while the non-textured sample should be equal to the amount of spherical hematite used ±5 wt.%. In an example where 15 wt.% spherical hematite is added to anisotropic goethite, the weight fraction of the unaligned phase should be 10-20 wt.%; if 25 wt.% of spherical hematite is added instead, the obtained weight fraction of the unaligned phase should be 20-30 wt.% and so forth.

3.3.3 - Electron backscatter diffraction (EBSD)

Electron backscatter diffraction (EBSD) is a scanning electron microscope (SEM) - based microstructural-crystallographic characterization technique commonly used in the study of crystalline or polycrystalline materials. An electron beam is rastered across the sample and the diffraction signal at each individual point is collected with a dedicated EBSD detector. At each point a Laue diffraction pattern is collected, and by indexing the pattern it is possible to determine the crystallographic phase and the orientation of the crystallites. EBSD may be performed in accordance with ISO 2417:2009

An example of a SEM/EBSD image of a highly aligned SrFeisO sample prepared from AC100 powder by SPS compaction is shown in Figure 10. Figure 10A is the orientation of the individuals grains obtained by indexing the individual diffraction spots, Figure 10B is an inverse pole figure revealing the vast majority of crystallites are aligned along the (00/) direction, i.e. the easy axis of the system.

In the bulk magnetic hexaferrites of the present invention comprising partial misaligned magnetic moments, the majority of a sample, such as 75%-85% of the sample will be aligned within ±15° of the easy axis, while the misaligned fraction will constitute 15-25%, with random orientation. Some of the randomly oriented samples will fall inside the 30° window around the easy axis - so the total number of randomly aligned non-anisotropic crystallites will be 13.5-22.5%. In the EBSD image this will be observed as crystallites having colours deviating from red. In the inverse pole figure this would mean that 13.5- 22.5% of the volume is misaligned with respect to the (00/) easy axis. Items

1 . A bulk magnetic material comprising an aligned magnetic part and a non- aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites; wherein the aligned magnetic part is uniformly aligned, and wherein the non- aligned magnetic part is not aligned, neither uniformly, nor with respect to the aligned magnetic part.

2. The bulk magnetic material according to item 1 , wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis of the bulk magnetic material.

3. The bulk magnetic material according to any one of items 1 to 2, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis of the bulk magnetic material.

4. The bulk magnetic material according to any one of items 1 to 3, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the surface normal of the bulk magnetic material.

5. The bulk magnetic material according to any one of items 1 to 4, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material. 6. The bulk magnetic material according to any one of items 3 to 5, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, such as within ±24°, such as within ±23°, such as within ±22°, such as within ±21 °, such as within ±20°, such as within ±19°, such as within ±18°, such as within ±17°, such as within ±16°, such as within ±15°, such as within ±14°, such as within ±13°, such as within ±12°, such as within ±11 °, such as within ±10°, such as within ±9°, such as within ±8°, such as within ±7°, such as within ±6°, such as within ±5°.

7. The bulk magnetic material according to any one of items 1 to 6, wherein the aligned, and non-aligned magnetic part of hexaferrite are individually selected from the group consisting of M-type hexaferrite, such as M-type strontium hexaferrite (SrFeisO ) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrite and X-type hexaferrite.

8. The bulk magnetic material according to any one of items 1 to 7, wherein the aligned, and non-aligned magnetic part of hexaferrite is M-type strontium hexaferrite (SrFeisO ).

9. The bulk magnetic material according to any one of items 1 to 8, wherein the aligned magnetic part constitutes 50 wt.% to 99 wt.% of the bulk part of the magnetic material, such as from 50 wt% to 60 wt.%, such as from 60 wt% to 70 wt.%, such as from 70 wt% to 75 wt.%, such as from 75 wt% to 80 wt.%, such as from 80 wt% to 85 wt.%, such as from 85 wt% to 90 wt.%, such as from 90 wt% to 95 wt.%, such as from 95 wt% to 99 wt%.

10. The bulk magnetic material according to any one of items 1 to 9, wherein the non-aligned magnetic part constitutes 1 wt.% to 50 wt.% of the bulk part of the magnetic material, such as from 1 wt.% to 5 wt.%, such as from 5 wt.% to 10 wt.%, such as from 10 wt.% to 15 wt.%, such as from 15 wt.% to 20 wt.%, such as from 20 wt.% to 25 wt.%, such as from 25 wt.% to 30 wt.%, such as from 30 wt.% to 40 wt.%, such as from 40 wt.% to 50 wt.%.

11 . The bulk magnetic material according to any one of items 1 to 10, further characterized by a coercivity ranging from 200 kA/m to 1000 kA/m. The bulk magnetic material according to claim 11 , wherein the coercivity of the bulk magnetic material is from 200 kA/m to 250 kA/m, such as from 250 kA/m to 300 kA/m, such as from 300 kA/m to 350 kA/m, such as from 350 kA/m to 375 kA/m, such as from 375 kA/m to 400 kA/m, such as from 400 kA/m to 425 kA/m, such as from 425 kA/m to 450 kA/m, such as from 450 kA/m to 500 kA/m, such as from 500 kA/m to 750 kA/m, such as from 750 kA/m to 1000 kA/m. The bulk magnetic material according to any one of items 1 to 12, wherein the aligned magnetic part is further characterized by an average aspect ratio A/C ranging from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100, such as from 100 to 125, such as from 125 to 150, such as from 150 to 200, such as from 200 to 400, such as from 400 to 500. The bulk magnetic material according to any one of items 1 to 13, wherein the non-aligned magnetic part is further characterized by an average aspect ratio A/C ranging from 3.0 to 1 .0, such as from 3.0 to 2.5, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0. The bulk magnetic material according to any one of items 1 to 14, wherein the material does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). A method for manufacturing a bulk magnetic material of hexaferrite, the bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, the method comprising the steps: a. Providing a first iron-based oxide comprising anisotropic crystallites, the anisotropic crystallites characterized by an average aspect ratio A/C is 5 to 500; b. Providing a second iron-based oxide comprising crystallites, the crystallites characterized by an average aspect ratio A/C < 3; c. Providing an amount of an alkaline earth metal (aem) precursor; d. Mixing said first and said second iron-based oxides with said alkaline earth metal (aem) precursor to obtain a final precursor mixture; e. Compacting said final precursor mixture by the application of uniaxial pressure of 200 MPa of 5000 MPa, thereby inducing alignment of the first iron-based precursor to obtain a partially aligned precursor, wherein the second iron-based precursor is not aligned by this step; f. Heating said partially aligned precursor, at a heating rate ranging from 10 °C/h to 10 °C/sec, to a temperature ranging from 1000 °C to 1250 °C, to convert said partially aligned precursor into said bulk magnetic material of hexaferrite; and g. Isolating the thus formed bulk magnetic material of hexaferrite comprising an aligned magnetic part and a non-aligned magnetic part from the reaction mixture.

17. The method according to item 16, wherein the hexaferrite is selected from the group consisting of M-type hexaferrite, X-type hexaferrite, and W-type hexaferrite.

18. The method according to any one of items16 to 17, wherein the hexaferrite is an M-type hexaferrite.

19. The method according to any one of items 17 to 18, wherein the M-type hexaferrite is selected from the group consisting of M-type strontium hexaferrite (SrPeisO ), M-type barium hexaferrite (BaFe^O ), M-type calcium hexaferrite (CaFeisO ) and substituents thereof.

20. The method according to any one of items 16 to 19, wherein the hexaferrite does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). The method according to any one of items 16 to 20, wherein the first iron-based oxide is selected from the group consisting of goethite, hematite, six-line ferrihydrite, and hexaferrites, such as M-type hexaferrites, preferably M-type strontium hexaferrite (SrFeisO ) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrites and X-type hexaferrites. The method according to any one of items 16 to 21 , wherein the first iron-based oxide is non-ferromagnetically interacting, such as non-ferromagnetic at ambient conditions. The method according to any one of items 16 to 22, wherein the first iron-based oxide is non-ferromagnetically interacting and is selected from goethite, hematite, or six-line ferrihydrite, preferably goethite. The method according to any one of items 16 to 23, wherein the average aspect ratio A/C of the first iron-based oxide is from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100, such as from

100 to 125, such as from 125 to 150, such as from 150 to 200, such as from 200 to 400, such as from 400 to 500. The method according to any one of items 16 to 24, wherein the second ironbased oxide is selected from the group consisting of M-type strontium hexaferrite (SrFeisO ), hematite, M-type barium hexaferrite (BaFeisO ), M- type calcium hexaferrite (CaFeisO ), goethite, W-type hexaferrites and X-type hexaferrites. The method according to any one of items 16 to 25, wherein the average aspect ratio A/C of the second iron-based oxide is from 3.0 to 1 .0, such as from 3.0 to 2.5, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to

1 .0, preferably from 2.0 to 1 .0. 27. The method according to any one of items 16 to 26, wherein the first iron-based oxide and the second iron-based oxide are mixed in a ratio ranging from 99:1 by weight to 50:50 by weight.

28. The method according to any one of items 16 to 27, wherein the mixing ratio ranges from 99:1 to 50:50 by weight, such as from 99:1 to 95:5, such as from 95:5 to 90:10, such as from 90:10 to 85:15, such as from 85:15 to 80:20, such as from 80:20 to 75:25, such as from 75:25 to 70:30, such as from 70:30 to 65:35, such as from 65:35 to 60:40, such as from 60:40 to 55:45, such as from 55:45 to 50:50.

29. The method according to any one of items 16 to 28, wherein the alkaline earth metal (aem) precursor is provided in an amount to obtain a Fe/aem molar ratio ranging from 8 to 14, such as from 8 to 9, such as from 9 to 10, such as from 10 to 10.5, such as from 10.5 to 11 such as from 11 to 11 .5, such as from 11 .5 to

12, such as from 12 to 13, such as from 13 to 14.

30. The method according to any one of items 16 to 29, wherein the alkaline earth metal (aem) precursor comprises an alkaline earth metal selected from the group consisting of Sr, Ba, Ca, Mg, Be and Ra.

31 . The method according to any one of items 16 to 30, wherein the alkaline earth metal (aem) is selected from the group consisting of Sr and Ba, preferably Sr.

32. The method according to any one of items 16 to 31 , wherein the alkaline earth metal (aem) precursor is selected as one or more from the group consisting of SrCO₃, SrO, Sr(OH)₂, SrCI₂, Sr(NO₃)₂, SrSO₄, Sr(OAc)₂, Sr₃(PO₄)₂, and hydrates thereof.

33. The method according to any one of items 16 to 32, wherein the alkaline earth metal (aem) precursor is selected as one or more from the group consisting of BaCO₃, BaO, Ba(OH)₂, BaCI₂, Ba(NO₃)₂, BaSO₄, Ba(OAc)₂, Ba₃(PO₄)₂, and hydrates thereof. The method according to any one of items 16 to 33, wherein the applied uniaxial pressure is from 200 MPa of 5000 MPa, such as from 200 MPa to 500 MPa, such as from 500 MPa to 650 MPa, such as from 650 MPa to 800 MPa, such as from 800 MPa to 1000 MPa, such as from 1000 MPa to 1200 MPa, such as from 1200 MPa to 1500 MPa, such as from 1500 MPa to 2000 MPa, such as from 2000 MPa to 3000 MPa, such as from 3000 MPa to 4000 MPa, such as from 4000 MPa to 5000 MPa. The method according to any one of items 16 to 34, wherein the temperature is from 1000 °C to 1250 °C, such as from 1050 °C to 1075 °C, such as from 1075 °C to 1100 °C, such as from 1100 °C to 1125 °C, such as from 1125 °C to 1150 °C, such as from 1150 °C to 1175 °C, such as from 1175 °C to 1200 °C, such as from 1200 °C to 1220 °C, such as from 1220 °C to 1240 °C, such as from 1240 °C to 1250 °C. The method according to any one of items 16 to 35, wherein the heating rate is from 10 °C/h to 10 °C/min, such as from 10 °C/h to 30°C/h, such as from 30 °C/h to 45 °C/h, such as from 45 °C/h to 1 °C/min, such as from 1 °C/min to 2 °C/min, such as from 2 °C/min to 5 °C/min, such as from 5 °C/min to 10 °C/min. A bulk magnetic material obtainable by the method according to any one of items 16 to 36. The bulk magnetic material according to item 37, wherein the bulk magnetic material is comprising an aligned magnetic part and a non-aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites; The bulk magnetic material according to any one of items 37 to 38, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material. 40. The bulk magnetic material according to any one of items 37 to 39, further characterized by a coercivity ranging from 200 kA/m to 1000 kA/m.

41 . The bulk magnetic material according to any one of items 37 to 40, wherein the aligned magnetic part constitutes 50 wt.% to 99 wt.% of the bulk part of the magnetic material.

42. The bulk magnetic material according to any one of items 37 to 41 , wherein the non-aligned magnetic part constitutes 1 wt.% to 50 wt.% of the bulk part of the magnetic material.

43. The bulk magnetic material according to any one of items 37 to 42, wherein the aligned, and non-aligned magnetic part of hexaferrite is M-type strontium hexaferrite (SrFeisO ).

44. The bulk magnetic material according to any one of items 37 to 43, wherein the material does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y).

45. Use of the bulk magnetic material according to any one of items 1 to 15 or 37 to 44, or the bulk magnetic material obtained by the method as defined in any one of items 16 to 36 as a magnetic component in a device.

46. The use according to items 45, wherein the device is an electric motor. Items 2

2. The bulk magnetic material according to item 1 , wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material.

3. The bulk magnetic material according to any one of items 1 to 2, wherein the aligned, and non-aligned magnetic part of hexaferrite is M-type strontium hexaferrite (SrFeisO ).

4. The bulk magnetic material according to any one of items 1 to 3, wherein the aligned magnetic part constitutes 70 wt.% to 90 wt.% of the bulk part of the magnetic material

5. The bulk magnetic material according to any one of items 1 to 4, further characterized by a coercivity ranging from 200 kA/m to 1000 kA/m.

6. The bulk magnetic material according to item 5, wherein the coercivity of the bulk magnetic material is from 350 kA/m to 450 kA/m.

7. The bulk magnetic material according to any one of items 1 to 6, wherein the material does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). A method for manufacturing a bulk magnetic material of hexaferrite, the bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, the method comprising the steps: a. Providing a first iron-based oxide comprising anisotropic crystallites, the anisotropic crystallites characterized by an average aspect ratio A/C is 5 to 500; b. Providing a second iron-based oxide comprising crystallites, the crystallites characterized by an average aspect ratio A/C < 3; c. Providing an amount of an alkaline earth metal (aem) precursor; d. Mixing said first and said second iron-based oxides with said alkaline earth metal (aem) precursor to obtain a final precursor mixture; e. Compacting said final precursor mixture by the application of uniaxial pressure of 200 MPa of 5000 MPa, thereby inducing alignment of the first iron-based precursor to obtain a partially aligned precursor, wherein the second iron-based precursor is not aligned by this step; f. Heating said partially aligned precursor, at a heating rate ranging from 10 °C/h to 10 °C/sec, to a temperature ranging from 1000 °C to 1250 °C, to convert said partially aligned precursor into said bulk magnetic material of hexaferrite; and g. Isolating the thus formed bulk magnetic material of hexaferrite comprising an aligned magnetic part and a non-aligned magnetic part from the reaction mixture. The method according to item 8, wherein the hexaferrite is M-type strontium hexaferrite (SrFeisO ), wherein the alkaline earth metal (aem) precursor is SrCOs, and wherein the hexaferrite is further characterized by not containing rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). The method according to any one of items 8 to 9, wherein the first iron-based oxide is selected from the group consisting of goethite, hematite, six-line ferrihydrite, and hexaferrites, such as M-type hexaferrites, preferably M-type strontium hexaferrite (SrFeisO ) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrites and X-type hexaferrites. The method according to any one of items 8 to 10, wherein the first iron-based oxide is non-ferromagnetically interacting and is selected from goethite, hematite, or six-line ferrihydrite, preferably goethite, and wherein the average aspect ratio A/C of the first iron-based oxide is from 5 to 100, such as from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100. The method according to any one of items 8 to 11 , wherein the second ironbased oxide is selected from the group consisting of M-type strontium hexaferrite (SrFeisO ), hematite, M-type barium hexaferrite (BaFeisO ), M- type calcium hexaferrite (CaFeisO ), goethite, W-type hexaferrites and X-type hexaferrites, and wherein the average aspect ratio A/C of the second ironbased oxide is from 3.0 to 1 .0, such as from 3.0 to 2.5, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0. The method according to any one of items 8 to 12, wherein the mixing ratio of the first iron-based oxide to the second iron-based oxide ranges from 99:1 to 50:50 by weight, and is preferably such as from 90:10 to 70:30. A bulk magnetic material obtainable by the method according to any one of items 8 to 13. Use of the bulk magnetic material according to any one of items 1 to 8 or 14, or the bulk magnetic material obtained by the method as defined in any one of items 8 to 13 as a magnetic component in a device, such as in an electric motor.

Claims

1 . A bulk magnetic material comprising an aligned magnetic part and a non- aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites; wherein the aligned magnetic part is uniformly aligned, and wherein the non- aligned magnetic part is not aligned, neither uniformly, nor with respect to the aligned magnetic part, and wherein the aligned, and non-aligned magnetic part of hexaferrite comprise or consist of M-type strontium hexaferrite (SrFeisO ).

2. The bulk magnetic material according to claim 1 , wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis of the bulk magnetic material.

3. The bulk magnetic material according to any one of claim 1 to 2, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis of the bulk magnetic material.

4. The bulk magnetic material according to any one of claims 1 to 3, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the surface normal of the bulk magnetic material.

5. The bulk magnetic material according to any one of claims 1 to 4, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material. The bulk magnetic material according to any one of claims 3 to 5, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, such as within ±24°, such as within ±23°, such as within ±22°, such as within ±21 °, such as within ±20°, such as within ±19°, such as within ±18°, such as within ±17°, such as within ±16°, such as within ±15°, such as within ±14°, such as within ±13°, such as within ±12°, such as within ±11 °, such as within ±10°, such as within ±9°, such as within ±8°, such as within ±7°, such as within ±6°, such as within ±5°. The bulk magnetic material according to any one of claims 1 to 6, wherein the aligned magnetic part constitutes 50 wt.% to 99 wt.% of the bulk part of the magnetic material, such as from 50 wt% to 60 wt.%, such as from 60 wt% to 70 wt.%, such as from 70 wt% to 75 wt.%, such as from 75 wt% to 80 wt.%, such as from 80 wt% to 85 wt.%, such as from 85 wt% to 90 wt.%, such as from 90 wt% to 95 wt.%, such as from 95 wt% to 99 wt%. The bulk magnetic material according to any one of claims 1 to 7, wherein the non-aligned magnetic part constitutes 1 wt.% to 50 wt.% of the bulk part of the magnetic material, such as from 1 wt.% to 5 wt.%, such as from 5 wt.% to 10 wt.%, such as from 10 wt.% to 15 wt.%, such as from 15 wt.% to 20 wt.%, such as from 20 wt.% to 25 wt.%, such as from 25 wt.% to 30 wt.%, such as from 30 wt.% to 40 wt.%, such as from 40 wt.% to 50 wt.%. The bulk magnetic material according to any one of claims 1 to 8, wherein the alignment is measured by electron backscatter diffraction (EBSD), such as in accordance with ISO 2417:2009. The bulk magnetic material according to any one of claims 1 to 9, further characterized by a coercivity ranging from 300 kA/m to 1000 kA/m when measured at 300 K in an external applied magnetic field cycled between ±3 T using a Vibrating Sample Magnetometer (VSM) operating at a frequency of 40 Hz and 50 Oe/s. 11 . The bulk magnetic material according to claim 10, wherein the coercivity of the bulk magnetic material is from 300 kA/m to 350 kA/m, such as from 350 kA/m to 375 kA/m, such as from 375 kA/m to 400 kA/m, such as from 400 kA/m to 425 kA/m, such as from 425 kA/m to 450 kA/m, such as from 450 kA/m to 500 kA/m, such as from 500 kA/m to 750 kA/m, such as from 750 kA/m to 1000 kA/m when measured at 300 K in an external applied magnetic field cycled between ±3 T using a Vibrating Sample Magnetometer (VSM) operating at a frequency of 40 Hz and 50 Oe/s.

12. The bulk magnetic material according to any one of claims 1 to 11 , wherein the aligned magnetic part is further characterized by an average aspect ratio A/C ranging from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100, such as from 100 to 125, such as from 125 to 150, such as from 150 to 200, such as from 200 to 400, such as from 400 to 500.

13. The bulk magnetic material according to any one of claims 1 to 12, wherein the non-aligned magnetic part is further characterized by an average aspect ratio A/C of less than 3.0, such as less than 2.8, such as less than 2.7, such as less than 2.6, such as from 2.5 to 1 .0, such as from 2.5 to 2.0, such as from 2.0 to

1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

14. The bulk magnetic material according to any one of claims 1 to 13, wherein the average aspect ratio A/C is as determined by crystallite sizes extracted from X- ray powder diffraction (XRD) analysis or from particle sizes extracted from Transmission Electron Microscopy (TEM) analysis, preferably as determined from particle sizes extracted from TEM.

15. The bulk magnetic material according to any one of claims 1 to 14, wherein the material does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). 16. The bulk magnetic material according to any one of claims 1 to 15, wherein the aligned magnetic part and non-aligned magnetic part are magnetically coupled, such as in a two-phase coupled magnetic system.

17. A method for manufacturing a bulk magnetic material of hexaferrite, the bulk magnetic material comprising an aligned magnetic part and a non-aligned magnetic part, each part comprising or consisting of M-type strontium hexaferrite (SrFeisO ), the method comprising the steps: a. Providing a first iron-based oxide comprising anisotropic crystallites, the anisotropic crystallites characterized by an average aspect ratio A/C is 5 to 500; b. Providing a second iron-based oxide in the form of M-type strontium hexaferrite (SrFeisO ), the second iron-based oxide comprising crystallites characterized by an average aspect ratio A/C < 3; c. Providing an amount of an alkaline earth metal (aem) precursor; d. Mixing said first and said second iron-based oxides with said alkaline earth metal (aem) precursor to obtain a final precursor mixture; e. Compacting said final precursor mixture by the application of uniaxial pressure of 200 MPa of 5000 MPa, thereby inducing alignment of the first iron-based precursor to obtain a partially aligned precursor, wherein the second iron-based precursor is not aligned by this step; f. Heating said partially aligned precursor, at a heating rate ranging from 10 °C/h to 10 °C/sec, to a temperature ranging from 1000 °C to 1240 °C, to convert said partially aligned precursor into said bulk magnetic material of hexaferrite; and g. Isolating the thus formed bulk magnetic material of hexaferrite comprising an aligned magnetic part and a non-aligned magnetic part from the reaction mixture, each part comprising or consisting of M- type strontium hexaferrite (SrPeisO ).

18. The method according to claim 17, wherein the hexaferrite does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). 19. The method according to any one of claims 17 to 18, wherein the first ironbased oxide is selected from the group consisting of goethite, hematite, six-line ferrihydrite, and hexaferrites, such as M-type hexaferrites, preferably M-type strontium hexaferrite (SrFeisO ) or M-type barium hexaferrite (BaFeisO ) or M-type calcium hexaferrite (CaFeisO ), W-type hexaferrites and X-type hexaferrites.

20. The method according to any one of claims 17 to 19, wherein the first ironbased oxide is non-ferromagnetically interacting, such as non-ferromagnetic at ambient conditions.

21 . The method according to any one of claims 17 to 20, wherein the first ironbased oxide is non-ferromagnetically interacting and is selected from goethite, hematite, or six-line ferrihydrite, preferably goethite.

22. The method according to any one of claims 17 to 21 , wherein the average aspect ratio A/C of the first iron-based oxide is from 5 to 10, such as from 10 to 15, such as from 15 to 20, such as from 20 to 30, such as from 30 to 40, such as from 40 to 50, such as from 50 to 75, such as from 75 to 100, such as from

100 to 125, such as from 125 to 150, such as from 150 to 200, such as from 200 to 400, such as from 400 to 500.

23. The method according to any one of claims 17 to 22, wherein the average aspect ratio A/C of the second iron-based oxide is less than 3.0, such as less than 2.8, such as less than 2.7, such as less than 2.6, such as from 2.5 to 1 .0, such as from 2.5 to 2.0, such as from 2.0 to 1 .5, such as from 1 .5 to 1 .0, preferably from 2.0 to 1 .0.

24. The method according to any one of claims 17 to 23, wherein the first ironbased oxide and the second iron-based oxide are mixed in a ratio ranging from 99:1 by weight to 50:50 by weight.

25. The method according to claim 24, wherein the mixing ratio ranges from 99:1 to 50:50 by weight, such as from 99:1 to 95:5, such as from 95:5 to 90:10, such as from 90:10 to 85:15, such as from 85:15 to 80:20, such as from 80:20 to 75:25, such as from 75:25 to 70:30, such as from 70:30 to 65:35, such as from 65:35 to 60:40, such as from 60:40 to 55:45, such as from 55:45 to 50:50.

26. The method according to any one of claims 17 to 25, wherein the alkaline earth metal (aem) precursor is provided in an amount to obtain a Fe/aem molar ratio ranging from 8 to 14, such as from 8 to 9, such as from 9 to 10, such as from 10 to 10.5, such as from 10.5 to 1 1 such as from 1 1 to 1 1 .5, such as from 1 1 .5 to

12, such as from 12 to 13, such as from 13 to 14.

27. The method according to any one of claims 17 to 26, wherein the alkaline earth metal (aem) precursor comprises an alkaline earth metal selected from the group consisting of Sr, Ba, Ca, Mg, Be and Ra.

28. The method according to any one of claims 17 to 27, wherein the alkaline earth metal (aem) is selected from the group consisting of Sr and Ba, preferably Sr.

29. The method according to any one of claims 17 to 28, wherein the alkaline earth metal (aem) precursor is selected as one or more from the group consisting of SrCO₃, SrO, Sr(OH)₂, SrCI₂, Sr(NO₃)₂, SrSO₄, Sr(OAc)₂, Sr₃(PO₄)₂, and hydrates thereof.

30. The method according to any one of claims 17 to 29, wherein the alkaline earth metal (aem) precursor is selected as one or more from the group consisting of BaCO₃, BaO, Ba(OH)₂, BaCI₂, Ba(NO₃)₂, BaSO₄, Ba(OAc)₂, Ba₃(PO₄)₂, and hydrates thereof.

31 . The method according to any one of claims 17 to 30, wherein the applied uniaxial pressure is from 200 MPa of 5000 MPa, such as from 200 MPa to 500 MPa, such as from 500 MPa to 650 MPa, such as from 650 MPa to 800 MPa, such as from 800 MPa to 1000 MPa, such as from 1000 MPa to 1200 MPa, such as from 1200 MPa to 1500 MPa, such as from 1500 MPa to 2000 MPa, such as from 2000 MPa to 3000 MPa, such as from 3000 MPa to 4000 MPa, such as from 4000 MPa to 5000 MPa. The method according to any one of claims 17 to 31 , wherein the temperature is from 1000 °C to 1240 °C, such as from 1050 °C to 1075 °C, such as from

1075 °C to 1100 °C, such as from 1100 °C to 1125 °C, such as from 1125 °C to 1150 °C, such as from 1150 °C to 1175 °C, such as from 1175 °C to 1200 °C, such as from 1200 °C to 1220 °C, such as from 1220 °C to 1240 °C. The method according to any one of claims 17 to 32, wherein the heating rate is from 10 °C/h to 10 °C/min, such as from 10 °C/h to 30°C/h, such as from 30 °C/h to 45 °C/h, such as from 45 °C/h to 1 °C/min, such as from 1 °C/min to 2 °C/min, such as from 2 °C/min to 5 °C/min, such as from 5 °C/min to 10 °C/min. A bulk magnetic material obtainable by the method according to any one of claims 17 to 33. The bulk magnetic material according to claim 34, wherein the bulk magnetic material is comprising an aligned magnetic part and a non-aligned magnetic part, wherein: a. the aligned magnetic part is hexaferrite hexagonal platelets; b. the non-aligned magnetic part is hexaferrite hexagonal crystallites; The bulk magnetic material according to any one of claims 34 to 35, wherein the aligned magnetic part is uniformly aligned with respect to the bulk magnetic material, wherein the magnetic easy axis of the aligned magnetic part coincides within ±25° of the surface normal of the bulk magnetic material, and wherein the non-aligned magnetic part is randomly oriented with respect to the magnetic easy axis and/or the surface normal of the bulk magnetic material. The bulk magnetic material according to any one of claims 34 to 36, further characterized by a coercivity ranging from 300 kA/m to 1000 kA/m. The bulk magnetic material according to any one of claims 35 to 37, wherein the aligned magnetic part constitutes 50 wt.% to 99 wt.% of the bulk part of the magnetic material. 39. The bulk magnetic material according to any one of claims 35 to 38, wherein the non-aligned magnetic part constitutes 1 wt.% to 50 wt.% of the bulk part of the magnetic material.

40. The bulk magnetic material according to any one of claims 35 to 39, wherein the aligned, and non-aligned magnetic part of hexaferrite is M-type strontium hexaferrite (SrFeisO ).

41 . The bulk magnetic material according to any one of claims 35 to 40, wherein the material does not contain rare-earth metals, such as lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y).

42. Use of the bulk magnetic material according to any one of claims 1 to 16 or 34 to 41 , or the bulk magnetic material obtained by the method as defined in any one of claims 17 to 33 as a magnetic component in a device.

43. The use according to claim 42, wherein the device is an electric motor.