KR20170142737A - Ferrite magnetic material and ferrite sintered magnet - Google Patents

Abstract

The present invention provides a ferrite magnetic material capable of providing high saturation magnetization and high anisotropic magnetic field by substituting a portion of La with Pr to provide a significantly higher maximum magnetic energy ((BH)_max) than a conventional ferrite magnetic materials.

Description

FIELD OF THE INVENTION [0001] The present invention relates to ferrite magnetic materials and ferrite sintered magnets,

The present invention relates to a ferrite magnetic material capable of providing a high maximum magnetic energy ((BH) _max ) and a ferrite sintered magnet using the ferrite magnetic material.

Ferrite has a magnetite-plumbite (M) type crystal structure in the composition of AO · nFe ₂ O ₃ (A: divalent metal ion, Sr or Ba) And is conventionally used as a material for a permanent magnet such as a motor for an automobile electric field and a rotator for an electric appliance. On the other hand, due to recent environmental problems and various laws related to energy saving, there is a demand for miniaturization and high efficiency of motors and high performance is required for permanent magnets.

M type ferrite is characterized by showing uniaxial crystal magnetic anisotropy. The chemical composition formula is represented by SrFe ₁₂ O ₁₉ or BaFe ₁₂ O ₁₉ , and there are 12 iron ions per molecule. The magnetic properties of the M-type ferrite are based on the magnetic moment of Fe ions, and there are 8 upward spin directions and 4 downward spin directions among the 12 Fe ions, The sum of the spins is 4. Generally, in the M type ferrite, the iron ion is trivalent (Fe ^{3 +} ), and the 3d electron (spin magnetic moment) is 5, and a total of 20 (5 spin moments × sum of pure spin) The spin magnetic moment becomes the source of magnetism (saturation magnetization) of the M-type ferrite magnet. That is, in order to increase the saturation magnetization value, which is the source of magnetism, substituting an element having a spin magnetic moment lower than an iron ion or a non-magnetic element in the downward spin direction of the iron ion increases the total spin magnetic moment, have. Element having a generally low spin magnetic moment than Fe ions and the like, Co ^{2 +} (spin moment = 3), Ni ^{2 +} (spin moment = 2) Cu ^{2 +} (spin moment = 1), a non-magnetic element Zn ^{2 +} (spin moment = 0). It is well known that substitution of iron ions (Fe ^{3 +} ) with Zn ^{2 +} theoretically maximizes the total spin magnetic moment to obtain a high saturation magnetization. However, although Zn has a high saturation magnetization, since it has a low anisotropic magnetic field, it has a low coercive force characteristic and is difficult to be used as a permanent magnet.

In addition, a high anisotropic magnetic field can be obtained by substituting an element having a large magnetocrystalline anisotropy into iron ions in M type ferrite for improving the magnetic anisotropy, which is an important magnetic property of the permanent magnet.

The residual magnetic flux density (Br), the intrinsic coercive force (iHc), the maximum magnetic energy ((BH) _max ) and the squareness ratio (Hknie / iHc) are typical magnetic characteristics of the permanent magnet. Have a relational expression.

Br = 4? I s 占 × 占 f (Is: saturation magnetization,?: Density, f: orientation degree)

iHc = H _A x fc (H _A : anisotropic magnetic field, fc: terminal volume ratio)

The residual magnetic flux density (Br) is proportional to the saturation magnetization, density and orientation degree, which is the sum of the magnetic spin moments of the composition. The density and the degree of orientation are about 95% Can be achieved. The theoretical saturation magnetization of strontium ferrite (hereinafter referred to as "Sr-ferrite") at room temperature is known to be 74 emu / g (4 pi Is = 4,760 G: value when density and orientation degree are respectively 100%), The saturation magnetization is increased by increasing the spin magnetic moment.

The intrinsic coercive force (iHc) is proportional to the anisotropic magnetic field and the terminal volume ratio, the theoretical anisotropy field value of the terminal sphere ferrite is 20,000 Oe, and the terminal sphere crystal size is known to be about 1 μm. Higher coercive force values can be obtained by increasing the volume ratio of the terminal sphere size by optimizing the process after the pulverization of the ferrite manufacturing process. It is possible to achieve about 40% (7,700 Oe) of the theoretical value by the internal semi-magnetic field when Sr-ferrite is the size of the terminal sphere, and higher anisotropic magnetic field value can be obtained by replacing Fe ion with an element having large magnetic anisotropy. However, since the anisotropic magnetic field and the saturation magnetization have a Trade off relation by the relation H _A = 2K ₁ / Is (2K ₁ : anisotropy coefficient), it is theoretically impossible to increase the saturation magnetization and the anisotropic field simultaneously by simple element substitution Do.

The maximum magnetic energy ((BH) _max ) is the product of the magnetic flux density (B) provided by the magnet at each operating point in the BH curve and the magnetic field (H) acting on the magnet, . On each demagnetization curve, the point at which the product of B and H is maximum is the maximum magnetic energy. In general, a permanent magnet having a high Br, iHc and squareness ratio has a high maximum magnetic energy ((BH) _max ), and a motor employing the permanent magnet has low output and little generation of potatoes due to an external magnetic field. As a result, the maximum magnetic energy is a representative performance index of permanent magnets.

For example, U.S. Patent No. 5,846,449 (Patent Document 1) discloses that when a part of Fe is substituted with Zn and a part of Sr is substituted with La, an improved saturation magnetization is obtained as compared with a conventional composition in which a part of Fe is substituted with Co And a ferrite magnet having a ferrite magnet can be obtained. However, when a part of Fe is substituted with Zn, there is a problem that the maximum magnetic energy is lowered to 5.14 MGOe due to a sharp reduction of anisotropic magnetic field.

Korean Patent Registration No. 10-0910048 (Patent Document 2) discloses that a part of Ca is replaced with a rare earth element such as La and a part of Fe is substituted with Co to improve the residual magnetic flux density and intrinsic coercive force, This results in a maximum magnetic energy output of 42.0 kJ / m ³ (about 5.28 MGOe). However, there is a problem that the magnetic property of the magnet obtained from Patent Document 2 is not sufficiently high as compared with the magnetic property of the conventional Sr ferrite magnet (Patent Document 1).

Further, in Korean Patent No. 10-1082389 (Patent Document 3), a part of Ca is substituted with Sr, Ba and La, and a part of Fe is substituted with Co and Cr to obtain a high residual magnetic flux density, intrinsic coercive force, However, the maximum magnetic energy of the magnet obtained by this method is 5.29 MGOe, which is not sufficiently high as compared with the conventional Sr ferrite magnet (Patent Document 1). In addition, this method has a disadvantage in that a complicated sintering process is applied in order to obtain high magnetic properties, resulting in an increase in manufacturing cost.

As described above, ferrite magnetic materials of known compositions still have unsatisfactory magnetic properties. In order to meet demands for high performance, high efficiency, miniaturization, and light weight of rotors and sensors used in automobiles, electric appliances, Development of magnetic materials having magnetic properties superior to those of magnetic materials has been required.

United States Patent No. 5,846,449 Korean Patent No. 10-0910048 Korean Patent No. 10-1082389

Accordingly, an object of the present invention is to provide a ferrite magnetic material capable of providing a high maximum magnetic energy by a high saturation magnetization and anisotropic magnetic field, and a ferrite sintered magnet obtained by sintering the ferrite magnetic material.

In order to achieve the above object, the present invention provides a ferrite magnetic material having a hexagonal magnetopermobite phase as a main phase and an element constituting the main phase comprising a composition represented by the following formula (1):

[Chemical Formula 1]

Ca _x Sr _(1-xyz) La _y Pr _z Fe _(2n-m) Co _m O ₁₉

In this formula,

0.46? X? 0.52,

0.32? Y? 0.39,

0.06? Z? 0.10,

0.91? X + y + z? 0.97,

0.25? M? 0.35,

9.0? 2n? 11.0.

As described above, the ferrite sintered magnet obtained from the ferrite magnetic material according to the present invention has a high maximum magnetic energy ((BH) _max ) and can meet the high efficiency and miniaturization of the motor required recently.

1 is a graph showing the change of each of the saturation magnetization (4 pi Is) and the anisotropic magnetic field (H _A ) according to the change of the content (z) of Pr of the ferrite sintered magnet obtained in Production Example 3.
2 is a graph of a change in the maximum magnetic energy ((BH) _max ) according to the change of the content (z) of Pr of the ferrite sintered magnet obtained in Production Example 3. FIG.
3 is a graph showing the change in the saturation magnetization (4 pi Is) and the anisotropic magnetic field (H _A ) according to the change in the sum (x + y + z) of the contents of Ca, La and Pr in the ferrite sintered magnet obtained in Production Example 4 .
4 is a graph of a change in maximum magnetic energy ((BH) _max ) according to a change in the sum (x + y + z) of contents of Ca, La and Pr in the ferrite sintered magnet obtained in Production Example 4. FIG.

As a result of continuous research to achieve the above object, the present inventors have found that, in a ferrite composition containing Ca, Sr, La and Co, a part of La is substituted with Pr, A ferrite magnetic material capable of providing a significantly higher maximum magnetic energy potential than a conventional ferrite magnetic material by high saturation magnetization and anisotropic magnetic field has been found and the present invention has been completed.

The ferrite magnetic material of the present invention has a magnetopermobite phase having a hexagonal system structure as a main phase, and the element constituting the main phase includes a composition represented by the following formula (1).

[Chemical Formula 1]

Ca _x Sr _(1-xyz) La _y Pr _z Fe _(2n-m) Co _m O ₁₉

When the content (x) of Ca is in the range of 0.46 to 0.52, a high saturation magnetization and anisotropic magnetic field are obtained, and thereby a high maximum magnetic energy potential can be obtained. When the content (x) of Ca is less than 0.46, the saturation magnetization is decreased due to the decrease of the substitutional amount of La and Pr and the maximum magnetic energy is lowered. When the Ca content is more than 0.52, saturation magnetization And the anisotropic magnetic field are largely reduced and the maximum magnetic energy potential is lowered.

The maximum content of magnetic energy can be obtained within a range of 0.32 to 0.39 in La content (y). When the content (y) of La is less than 0.32, the substitutional solubility of La is not sufficient and the maximum magnetic energy required in the present invention can not be obtained. When the content (y) exceeds 0.39, generation of non-magnetic phase such as orthoferrite The saturation magnetization and the anisotropic magnetic field may be reduced and the maximum magnetic energy potential may be lowered.

The maximum content of magnetic energy can be obtained within a range of the content (z) of Pr of 0.06 to 0.10. When the content (z) of Pr is less than 0.06, the substitutional amount of Pr is insufficient and a high maximum magnetic energy potential can not be obtained. When the content (z) is more than 0.10, the saturation magnetization and the anisotropic magnetic field are decreased by excessive substitution, Problems can arise.

The sum of the contents of Ca, La and Pr (x + y + z) is in the range of 0.91 to 0.97, whereby a maximum magnetic energy potential can be obtained. Specifically, the sum (x + y + z) of the contents of Ca, La and Pr may be in the range of 0.91 to 0.95. When the sum of the contents of Ca, La, and Pr is less than 0.91, the saturation magnetization and the anisotropic magnetic field are reduced due to a decrease in the substitutional amount of Co, resulting in a decrease in the maximum magnetic energy, and when it exceeds 0.97, The saturation magnetization and the anisotropic magnetic field may be reduced and the maximum magnetic energy may be lowered.

It is possible to obtain a maximum magnetic energy of a high Co content (m) in the range of 0.25 to 0.35. Specifically, the content (x) of Co may be in the range of 0.28 to 0.35. When the content (m) of Co is less than 0.25, the substitutional solubility of Co is insufficient and the maximum magnetic energy required in the present invention can not be obtained. When the Co content is more than 0.35, the saturation magnetization and the maximum magnetic energy There may be a problem of deterioration.

2n is a value representing a content ratio of (Fe + Co) / (Ca + Sr + La + Pr). When 2n is in the range of 9.0 to 11.0, a high maximum magnetic energy potential is obtained. When 2n is less than 9.0, the content of Ca + Sr + La + Pr is relatively increased, and the substitutional excess amount is exceeded, whereby the saturation magnetization and the anisotropic magnetic field are reduced, and the maximum magnetic energy equivalent can be reduced. When 2n exceeds 11.0, the saturation magnetization and the anisotropic magnetic field are reduced by the influence of the unreacted? -Fe ₂ O ₃ , and thus the maximum magnetic energy potential can be reduced.

A ferrite magnetic material and a method of manufacturing the sintered magnet according to an embodiment of the present invention are as follows.

<Mixing Process>

First, the starting material is converted into weight% from a predetermined ratio of each element, and then weighed. Typically, the mixing equipment is a wet-type ball mill or a wet-type attritor to wet-mix the starting material, wherein the wet ball mill for 5 to 10 hours, the wet attritor for 2 to Mix thoroughly evenly for 4 hours. SrCO ₃ , CaCO ₃ , La ₂ O ₃ , Fe ₂ O ₃ , Co ₃ O ₄ , Pr ₆ O ₁₁ and the like constituting the ferrite sintered magnet can be used as the starting material. In order to promote the ferrite reaction and uniform the growth of the particles at a low calcining temperature at the time of firing, 0.05 to 0.2 parts by weight of H ₃ BO ₃ based on 100 parts by weight of the starting material may be further mixed into the starting material.

&Lt; Firing step &

The calcining step is a step of calcining the raw material of the composition blended and blended in the previous step to produce a calcined body having a M (magnetoplumbite) structure together with the ferrite reaction. Usually, the calcining is performed in an oxidizing atmosphere in the air. The calcination is preferably performed at a temperature in the range of 1,150 to 1,250 DEG C for 30 minutes to 2 hours. The longer the calcination time, the higher the proportion of M phase, but this leads to an increase in the manufacturing cost. The proportion of the M phase, which is the main phase of the plasticizer, is preferably 90% or more, and the particle size in the structure is preferably 2 to 4 탆.

< Rough grinding  Process>

The calcined state after calcination can be roughly pulverized because it is generally a granule or a clinker state. The crushing means may be a dry vibration mill or a dry ball mill, and it is preferable to use a dry vibration mill. The average particle size of the powder after the coarse grinding (that is, the coarsely pulverized powder) may be 2 to 4 탆.

<Milling Process>

Sufficient magnetic properties can be obtained when the average particle diameter of the fine powder is 0.6 to 0.8 mu m in the fine pulverizing step. If the average particle size of the fine particles is within the above-mentioned range, there is a problem that the orientation property is deteriorated due to particle agglomeration between the ferrite magnetic powders to deteriorate the magnetic properties, leakage of the slurry occurs at the time of molding, And coercive force are rapidly reduced, and a large amount of heat energy is required to secure a sufficient sintered density, so that the problem of increase in manufacturing cost can be prevented.

The pulverizing time can be adjusted according to the grinding machine and the target particle diameter because the pulverizing time is inversely proportional to the pulverizing energy and the time varies depending on the pulverizer type.

In order to control the growth and inhibition of the particles during sintering and control the size of the crystal grain size, SiO ₂ , CaO, Fe ₂ O ₃ , La ₂ O ₃ and Co ₃ O ₄ And the like may be added. If the added amount of the additive is too small, the effect is insignificant. If the additive is added too much, negative effects may occur. Therefore, the additive may be added in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the coarse pulverized powder.

In addition, a dispersant may be added in order to improve the fluidity of the slurry during the magnetic field shaping and to lower the viscosity and the orientation effect. As the dispersant, both an aqueous dispersant and a non-aqueous dispersant can be used. However, A dispersant may be used. As the aqueous dispersing agent, an organic compound having a hydroxyl group and a carboxyl group, sorbitol, calcium gluconate and the like can be used. The dispersant may be added in an amount of 0.1 to 1.0 part by weight based on 100 parts by weight of the coarse pulverized powder. When the amount of the dispersant added is within the above range, the problem of deterioration of the dewatering property and cracking during drying and sintering of the molded article can be prevented.

&Lt; Molding step &

The molding process can be carried out by a wet anisotropic molding method, and a molding of an anisotropic sintered magnet is obtained by press molding while applying a magnetic field during molding.

For example, in wet anisotropic molding, the slurry is dehydrated and concentrated after finely pulverized to perform molding in a magnetic field while maintaining a predetermined concentration. The dewatering and concentration may be performed by using a centrifugal separator or a filter press. The slurry concentration may be 60 to 66 wt%, the forming pressure may be 0.3 to 0.5 ton / cm 2, and the applied magnetic field may be 10 to 20 kOe.

In order to prevent this, it is preferable to use natural drying or low temperature (50 to 100 ° C) in the atmosphere in order to prevent cracking in the dehydration process at the time of heating, After drying, sintering can be performed.

<Drying and Sintering Process>

Generally, a ferrite sintered magnet is obtained by successively drying and sintering a formed body in an atmospheric oxidizing atmosphere. Dehydration and degreasing can be performed at 50 to 100 占 폚 in order to remove moisture remaining in the molded body and degrease the dispersant.

In the sintering process, the magnetic properties of the ferrite sintered magnet can be enhanced by controlling the sintering conditions such as the heating rate, the maximum temperature, the maximum temperature holding time, and the cooling rate. For example, according to sintering conditions (sintering time, heating rate, maximum temperature, holding time), it is possible to control the concentration of solute in the crystal grain of the ferrite sintered magnet, the grain growth control, the grain size uniformity and the density of the sintered magnet, The degree of orientation can be controlled to control the magnetic properties. Sintering at a temperature rising time of 1 to 10 占 폚 / min and a sintering maximum temperature of 1,150 to 1,250 占 폚 for 30 minutes to 2 hours, and cooling at a cooling time of 1 to 10 占 폚 / min.

In this way, the magnet plume byte type ferrite sintered magnet of the present production invention while the saturation magnetization (4πIs) is more than 4.8 kG anisotropy field (H _A) 26 kOe time or more, the maximum self-energetic ((BH) _max) is 5.6 MGOe Or more.

The 4? I-H curve relates to the magnetization, which means a magnetic field by applying a magnetic field to a magnetic body to produce a magnetic moment and a magnetic polarization, and shows the characteristic of the inside of the magnet (inherent magnet).

Further, the present invention provides a permanent magnet such as a segment type or block type derived from the ferrite magnetic material as described above.

Furthermore, the permanent magnets of the present invention can be used for rotors, sensors, and bonded magnets used in automobiles, electric appliances, and home appliances.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are intended to illustrate the present invention, but the scope of the present invention is not limited thereto.

[ Example ]

Reference Example . Magnetic property measurement

The maximum magnetic energy ((BH) _max ) of the ferrite sintered magnet produced in the following Production Example was measured using a BH Curve Tracer with a maximum applied magnetic field of 25 kOe (1,990 kA / m) in an atmosphere of 20 ° C. After the ferrite sintered magnet was cut to a width of 5 mm and a thickness of 5 mm, the saturation magnetization (4 pi I s) and the anisotropic magnetic field (H _A ) in a quadrant of 4? I-H curves were measured with respect to a plane parallel to the perpendicular plane, Respectively.

Manufacturing example  One.

Manufacturing example  1-1: Mixing process

(Fe ₂ O ₃ , purity of 99% or more), strontium carbonate (SrCO ₃ ), calcium carbonate (CaCO ₃ ), lanthanum oxide (La ₂ O ₃ ), cobalt oxide (Co ₃ O ₄ ) and praseodymium oxide (Pr ₆ O ₁₁ ) was used. These starting materials were blended so as to obtain ferrite magnets of Ca _x Sr _(1-xyz) La _y Pr _z Fe _(2n-m) Co _m O ₁₉ satisfying the composition shown in Table 1 below. 0.1 wt% of H ₃ BO ₃ was added to the blended raw material in order to accelerate the ferrite reaction. The blended raw materials were mixed with water to a concentration of 40% by weight, followed by wet circulation mixing for 2 hours. The raw material thus formed was dried at 130 DEG C for 24 hours.

Manufacturing example  1-2: Plasticizing process

The powder dried in Preparation Example 1-1 was calcined at 1,200 DEG C for 1 hour in the atmosphere to obtain a calcined body.

Manufacturing example  1-3: Rough grinding  And a fine grinding step

A crude pulverized powder having an average particle size of 4 탆 was obtained from the calcined product of Production Example 1-2 using a dry vibration mill. In order to finely pulverize the coarsely pulverized powder, coarse pulverized powder and water were added to the circulating attritor so that the coarse pulverized powder had a concentration of 40% by weight, and CaO 0.35% by weight, 0.3% by weight of SiO ₂ and 0.3% by weight of calcium gluconate were added (based on the total content of the coarse pulverized powder) to obtain a sintered body composition as shown in Table 1 below. The mean particle size of the powder after the fine pulverization was set to be 0.65 mu m.

Manufacturing example  1-4: Molding process

The slurry as a mixture of the pulverized powder and water obtained in Preparation Example 1-3 was dehydrated so that the concentration of the pulverized powder was 63% by weight. The slurry thus obtained was pulverized in a disk type (diameter 40 mm X thickness 11 mm). At this time, the magnetic field intensity was set to 10 kOe (796 kA / m) and the molding pressure was set to 0.4 Ton / cm2.

Manufacturing example  1-5: Sintering process

The compact obtained in Production Example 1-4 was sintered at 1,210 占 폚 for 1 hour, and the obtained sintered compact was processed to a thickness of 7 mm using a double-side thickness processing machine to obtain a ferrite sintered magnet. The magnetic properties of the resulting ferrite sintered magnet were measured and are shown in Table 1 below.

sample Ca
(x) Sr (1-x-y-z) La
(y) Pr
(z) Fe
(2n-m) Co
(m) 2n Ca + La + Pr (x + y + z) 4πIs
(kG) H _A
(kOe) (BH) _max
(MGOe) One 0.40 0.15 0.37 0.08 10.50 0.34 10.84 0.85 4.77 24.2 5.25 2 0.43 0.12 0.37 0.08 10.50 0.34 10.84 0.88 4.78 25.0 5.40 3 0.46 0.09 0.37 0.08 10.50 0.34 10.84 0.91 4.82 26.0 5.62 4 0.49 0.06 0.37 0.08 10.50 0.34 10.84 0.94 4.84 26.7 5.64 5 0.52 0.03 0.37 0.08 10.50 0.34 10.84 0.97 4.84 27.1 5.65 6 0.55 0.00 0.37 0.08 10.50 0.34 10.84 1.00 4.78 25.5 5.43

As shown in Table 1, Samples 1, 2 and 6 correspond to comparative examples of the present invention, and Samples 3 to 5 correspond to the embodiments of the present invention. (BH) _max ) of 5.6 MGOe or more when the Ca content (x) is 0.46 to 0.52, which is significantly higher than the comparative example in which the Ca content (x) is out of the above range Respectively.

In addition, there was a range (x) of Ca in which the anisotropic magnetic field H _A increases as the saturation magnetization (4 pi Is) increases. When the Ca content is within the above range, the problem that the substitutional solubility of La and Pr is decreased or the maximum magnetic energy potential is decreased due to an increase in phase instability can be prevented.

Manufacturing example  2.

Ferrite sintered magnets were produced in the same manner as in Production Example 1 except that the content ratio (La) of La was changed as shown in Table 2 below. The magnetic properties of the obtained ferrite sintered magnets were measured and shown in Table 2 below.

sample Ca
(x) Sr
(1-xyz) La
(y) Pr
(z) Fe
(2n-m) Co
(m) 2n Ca + La + Pr
(x + y + z) 4πIs
(kG) H _A
(kOe) (BH) _max
(MGOe) 7 0.47 0.15 0.29 0.09 10.50 0.34 10.84 0.85 4.79 25.5 5.50 8 0.50 0.08 0.32 0.10 10.50 0.34 10.84 0.92 4.81 26.5 5.61 9 0.49 0.06 0.35 0.10 10.50 0.34 10.84 0.94 4.83 26.7 5.63 10 0.49 0.06 0.37 0.08 10.50 0.34 10.84 0.94 4.84 26.4 5.62 11 0.48 0.05 0.39 0.08 10.50 0.34 10.84 0.95 4.84 26.4 5.62 12 0.47 0.04 0.41 0.08 10.50 0.34 10.84 0.96 4.82 25.2 5.54

As shown in Table 2, Samples 7 and 12 correspond to Comparative Examples of the present invention, and Samples 8 to 11 are Examples of the present invention. When the La content (y) was 0.32 to 0.39, the maximum magnetic energy of 5.6 MGOe or more was obtained. When the content of La is within the above range, the substitutional solubility of La is insufficient or the problem of the saturation magnetization and the anisotropic magnetic field being reduced by the generation of the non-magnetic phase can be prevented.

Manufacturing example  3.

Ferrite sintered magnets were produced in the same manner as in Production Example 1 except that the content (z) of Pr was changed as shown in Table 3 below. The changes in the saturation magnetization (4 pi Is) and the anisotropic magnetic field (H _A ) as the result of variation in the Pr content of the obtained ferrite sintered magnet are shown in Table 3, (BH) _max ) at the maximum magnetic energy is shown in Fig.

sample Ca
(x) Sr
(1-xyz) La
(y) Pr
(z) Fe
(2n-m) Co
(m) 2n Ca + La + Pr
(x + y + z) 4πIs
(kG) H _A
(kOe) (BH) _max
(MGOe) 13 0.50 0.10 0.38 0.02 10.50 0.34 10.84 0.90 4.75 25.8 5.27 14 0.47 0.10 0.39 0.04 10.50 0.34 10.84 0.90 4.77 26.0 5.50 15 0.47 0.09 0.38 0.06 10.50 0.34 10.84 0.91 4.82 26.8 5.63 16 0.47 0.07 0.38 0.08 10.50 0.34 10.84 0.93 4.83 27.0 5.64 17 0.47 0.05 0.38 0.10 10.50 0.34 10.84 0.95 4.83 26.8 5.61 18 0.47 0.03 0.38 0.12 10.50 0.34 10.84 0.97 4.77 25.9 5.55 19 0.45 0.03 0.38 0.14 10.50 0.34 10.84 0.97 4.75 25.4 5.50

As shown in Table 3, Figs. 1 and 2, Samples 13, 14, 18 and 19 correspond to comparative examples of the present invention, and Samples 15 to 17 are examples of the present invention. When the content (z) of Pr was 0.06 to 0.10, the maximum magnetic energy of 5.6 MGOe or more was obtained. Also, there was a content range of Pr in which the anisotropic magnetic field was increased as the saturation magnetization was increased. When the content of Pr is within the above range, it is possible to prevent the problem that the substitutional amount of Pr is insufficient or the saturation magnetization and the anisotropic magnetic field due to excessive substitution are reduced and the maximum magnetic energy is lowered.

Manufacturing example  4.

Ferrite sintered magnets were produced in the same manner as in Production Example 1 except that the sum of the contents of Ca, La and Pr (x + y + z) was set to the composition ratio shown in Table 4 below. The magnetic properties of the resulting ferrite sintered magnet were measured and shown in Table 4. The saturation magnetization (4 pi Is) and the anisotropic magnetic field (H _A ) of the ferrite sintered magnet obtained by the change in the sum of Ca, The change is shown in Fig. 3, and the change of the maximum magnetic energy ((BH) _max ) is shown in Fig.

sample Ca
(x) Sr
(1-xyz) La
(y) Pr
(z) Fe
(2n-m) Co
(m) 2n Ca + La + Pr
(x + y + z) 4πIs
(kG) H _A
(kOe) (BH) _Max
(MGOe) 20 0.45 0.15 0.32 0.08 10.50 0.34 10.84 0.85 4.75 25.7 5.25 21 0.46 0.12 0.34 0.08 10.50 0.34 10.84 0.88 4.77 26.0 5.41 22 0.47 0.09 0.36 0.08 10.50 0.34 10.84 0.91 4.84 26.8 5.64 23 0.48 0.05 0.38 0.09 10.50 0.34 10.84 0.95 4.84 26.7 5.64 24 0.50 0.03 0.39 0.08 10.50 0.34 10.84 0.97 4.82 26.7 5.62 25 0.50 0.01 0.41 0.08 10.50 0.34 10.84 0.99 4.77 25.5 5.43

As shown in Table 4, Figs. 3 and 4, Samples 20, 21 and 25 correspond to Comparative Examples of the present invention, and Samples 22 to 24 are embodiments of the present invention. (X + y + z) of contents of Ca, La and Pr was obtained when the sum of contents of Ca, La and Pr (x + y + z) was 0.91 to 0.97, Was significantly higher than that of the comparative example deviating from the above range. In addition, there was a range of (x + y + z) of contents of Ca, La and Pr whose anisotropic magnetic field increases as the saturation magnetization increases. When the sum of the contents of Ca, La and Pr (x + y + z) is within the above range, the substitutional amount of Co decreases, or the formation of a nonmagnetic phase due to excessive substitution of Ca, La and Pr or the like causes saturation magnetization and anisotropy It is possible to prevent the problem that the magnetic field is reduced and the maximum magnetic energy potential is lowered.

Manufacturing example  5.

Ferrite sintered magnets were produced in the same manner as in Production Example 1 except that the content (m) of Co was changed as shown in Table 5. The magnetic properties of the obtained ferrite sintered magnets were measured and shown in Table 5 below.

sample Ca
(x) Sr
(1-xyz) La
(y) Pr
(z) Fe
(2n-m) Co
(m) 2n Ca + La + Pr
(x + y + z) 4πIs
(kG) H _A
(kOe) (BH) _Max
(MGOe) 26 0.47 0.07 0.38 0.08 10.50 0.19 10.69 0.93 4.79 25.0 5.20 27 0.48 0.06 0.38 0.08 10.50 0.22 10.72 0.94 4.80 25.6 5.45 28 0.47 0.07 0.38 0.08 10.50 0.25 10.75 0.93 4.82 26.5 5.61 29 0.47 0.07 0.38 0.08 10.50 0.28 10.78 0.93 4.83 26.7 5.63 30 0.48 0.06 0.38 0.08 10.50 0.31 10.81 0.94 4.84 26.8 5.64 31 0.48 0.06 0.38 0.08 10.50 0.35 10.85 0.94 4.83 26.8 5.63 32 0.47 0.07 0.38 0.08 10.50 0.38 10.88 0.93 4.78 26.7 5.46 33 0.48 0.06 0.38 0.08 10.50 0.41 10.91 0.94 4.75 26.8 5.18

As shown in Table 5, the samples 26, 27, 32 and 33 correspond to the comparative example of the present invention, and the samples 28 to 31 are the embodiments of the present invention. When the content (m) of Co was 0.25 to 0.35, a maximum magnetic energy of 5.6 MGOe or more was obtained. When the Co content ratio (m) is within the above range, the problem of the decrease of the saturation magnetization and the anisotropic magnetic field due to the reduction of the substitutional high-molecular weight decreases the maximum magnetic energy, Could.

Manufacturing example  6.

Ferrite sintered magnets were produced in the same manner as in Production Example 1 except that the content ratio (2n) of (Fe + Co) / (Ca + Sr + La + Pr) was changed as shown in Table 6 below. The magnetic properties were measured and are shown in Table 6 below.

sample Ca
(x) Sr
(1-xyz) La
(y) Pr
(z) Fe
(2n-m) Co
(m) 2n Ca + La + Pr
(x + y + z) 4πIs
(kG) H _A
(kOe) (BH) _Max
(MGOe) 34 0.48 0.17 0.27 0.08 8.00 0.30 8.30 0.83 4.75 25.5 5.25 35 0.49 0.09 0.34 0.08 8.70 0.30 9.00 0.91 4.83 26.3 5.61 36 0.48 0.08 0.36 0.08 9.50 0.34 9.84 0.92 4.83 26.7 5.63 37 0.48 0.08 0.36 0.08 10.00 0.33 10.33 0.92 4.83 27.0 5.64 38 0.48 0.08 0.36 0.08 10.60 0.35 10.95 0.92 4.81 27.2 5.64 39 0.48 0.08 0.36 0.08 11.00 0.34 11.34 0.92 4.80 25.8 5.41

As shown in Table 6, Samples 34 and 39 correspond to Comparative Examples of the present invention, and Samples 35 to 38 correspond to Examples of the present invention. 2n was 9.0 to 11.0, the maximum magnetic energy of 5.6 MGOe or more could be obtained. When 2n is within the above range, the content of Ca + Sr + La + Pr becomes relatively large, so that nonmagnetic property due to exceeding the high capacity is generated, and the maximum magnetic energy is decreased and unreacted? -Fe ₂ O ₃ is produced The problem of the maximum magnetic energy reduction can be prevented.

Claims (4)

1. A ferrite magnetic material comprising a main phase of a magnetoplumbite phase having a hexagonal system structure and an element constituting a main phase of the ferrite magnetic material,
[Chemical Formula 1]
Ca _x Sr _(1-xyz) La _y Pr _z Fe _(2n-m) Co _m O ₁₉
In this formula,
0.46? X? 0.52,
0.32? Y? 0.39,
0.06? Z? 0.10,
0.91? X + y + z? 0.97,
0.25? M? 0.35,
9.0? 2n? 11.0.
The method according to claim 1,
Wherein the x + y + z value is 0.91? X + y + z? 0.95.
The method according to claim 1,
Wherein the m value is 0.28? M? 0.35.
A ferrite magnetic material obtained by sintering the ferrite magnetic material according to any one of claims 1 to 3,
_A ferrite sintered magnet having a maximum magnetic energy ((BH) _max ) of 5.6 MGOe or more when the saturation magnetization (4 pi Is) is 4.8 kG or more and the anisotropic magnetic field (H _A ) is 26 kOe or more.

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