JPS63203745A - Iron-containing magnetic material - Google Patents

Abstract

The new magnetic material containing iron contains at least three alloy components R, iron (Fe) and M, a tetragonal ThMn12 structure being formed. The material proportion of the Fe component is intended to be at least 60% by atomic weight. According to the invention, it is provided that at least one rare-earth metal is selected for R, and molybdenum (Mo) and/or tungsten (W) are selected for M, the Fe proportion being at most 85% by atomic weight and the R and M proportion being between 2 and 20% by atomic weight and 4 and 35% by atomic weight, respectively. As well as the phase with the ThMn12 structure, the material can have at least one further phase of the R-Fe-M system. In particular, it can also be a component of mixed or composite materials. <IMAGE>

Description

Detailed description of the invention [Industrial field of application] The present invention has at least three alloy components R5 iron (Fe) and M, and the material content of the iron component is at least 60 atomic %.
and relates to an iron-containing magnetic material in which a tetragonal ThMn12 structure is formed.

[Conventional technology]

Materials with this type of structure are known, for example, in the literature “Journal
Journal of Applied Physics
pplied Physics) J 53rd t1 3rd
No. 2077-2078, March 1981.

Known hard magnetic ternary material neodymium (Nd) with high energy production and relatively low Chieri temperature of 300 °C
-Iron (Fe) -Boron (B) is mainly Nd2Fe1
4B and Nd++, s f'e@1.3 Bs, (for example, the above-mentioned literature (J, ^pp
1. Phys, ) Volume 55 No. 6 Part 2 1984 3
(see page 2083-2087), in this case the unit cell (
A large number of iron atoms from the 68 atoms in P4m/Kaku) form two layers with a sigma-like structure. The tight packing and high content of iron result in a high saturation magnetization of the phase M s (300 to 1.
67), and the addition of light rare earth metals is responsible for the complex structure of the unit cell as well as the remarkable magnetocrystalline anisotropy (anisotropy field strength Ha is about 9 T at 300) (for example, in the literature “Solid-state・Comiunication (Soli)
d 5tate Cos+sun, ) J Volume 51 No. 11
No. 857-860, September 1984), and further Nd
, Fe, and B with other rare earth metals, transition elements, and nonmetals are also being investigated. That is, for example, the document mentioned at the beginning (J, ^pp1.Phys,)
describes the structure and magnetic properties of a special ternary system of R-Fe-M type. In this case, R is yttrium (Y)
, M is manganese (Mn), this ternary system has inter alia its stoichiometric composition Y (MnI--Fe-)
+z forms an anisotropic tetragonal Tb1all structure,
This is antiferromagnetic, and the corresponding structure has an intermetallic phase with 26 atoms in the unit cell (space group 14/■).
This structure is abbreviated (Reference Schubert (K,
``Binary phase crystal structure
allstrukturen zweiko+mpon
Springer
Published 1964, pp. 166-167), in which case the solid black circles in the drawing represent individual lattice points occupied by Mo, while the hollow circles indicate layers of Be lattice points, corresponding to The structure can also be confirmed for the above system Y (MnI-m Fe, I)t* with iron content up to x-0,67. It is possible to observe the second phase of hexagonal structure ThtZlv.

[Problem to be solved by the invention]

The division of the present invention is able to modify its magnetic properties, such as Chieri temperature, magnetic moment, anisotropic crystal structure or magnetic anisotropy, by selecting the individual alloy partners and their respective contents in the alloy. The object of the present invention is to provide an iron-containing magnetic material that can be modified and manufactured relatively inexpensively.

[Means to solve the problem]

This task is achieved according to the invention, starting from an iron-containing magnetic material of the type mentioned at the outset, containing as R at least one element selected from the group of rare earth metals and as M molybdenum (Mo) and/or It has tungsten (W) with a Fe content of up to 85 at% and an R content of 2.
~20 at%, and the Mo and/or W content is 4
This is solved by being 35 atomic %.

[Effect]

The material according to the invention therefore contains a large amount of Fe, which has a high magnetic moment and is cost-effective, without the need for non-metals such as B, Sl or Ge, for example. By the way, the present invention uses a composition R-Fe-M.

and the recognition that an alloy consisting of at least the three components R-Fe-W has magnetic properties such as a Curie temperature in the range of about 100°C to 200°C and a saturation magnetization in the range of about 0.6 to 1.0 Tesla, for example. The inclusion of the abovementioned percentages of the lateral alloying components in this case ensures that at least a large amount of the ThMnt* phase, which is advantageous with respect to the magnetic properties, is present in the material. In the case of some alloying components, which can be selected from the group of rare earth metals, in particular gadolinium (Gd) or samarium (Sm), additionally lead to magnetic anisotropy. Furthermore, by adding other components of the above-mentioned ternary system, particularly by adding cobalt (Co), the Curie temperature or saturation magnetization can be increased in some cases.

The material according to the present invention does not need to consist solely of a phase having a tetragonal ThMn structure including unavoidable impurities, but rather may contain phases other than the above-mentioned alloy components.

Furthermore, the material according to the invention may advantageously be integrated into or laminated to other materials, so that the material forms, for example, a component of a mixture or composite material.

Another advantageous embodiment of the magnetic material according to the invention is as claimed in claim 2.
Described below.

〔Example〕

The invention will now be explained in more detail on the basis of examples and in conjunction with the drawings. In this case, FIG. 1 is a graph showing a part of an isothermal cross-sectional view of the ternary system Fe--Mo--Nd. Figure 2 shows the magnetization curve in relation to temperature for a special F@sJO+tR* alloy, and Figures 3 and 4 show the Curie temperature of this phase in comparison with the known material F@+aRJ. and saturation magnetization.

In this case, R is any rare earth metal, in particular cerium (Ce), neodymium, IA (Nd), samarium (Sm).
), gadolinium CGd), dysprosium (Dy)
and means the element erbium (Er). R may optionally be a combination of several rare earth metals.

To produce the material according to the invention of the composition R-Fe-Mo, starting from 99.9% of each individual rare earth metal with a content of 99.97% of Fe and Mo and a maximum of 1000 pp of rare earth oxide. Immediately before processing, the rare earth metal is cut into pieces with a saw to a suitable size, and its surface is cleaned by wet sanding and ultrasonic treatment in water and subsequently in ethanol. The alloying components are then melted in a water-cooled copper vessel under argon as a protective gas by the heat obtained by a high-frequency generator, first of all the Fe and M
o is liquefied and then the respective rare earth metal is added. The resulting ternary alloy is typically liquefied on a vessel with radio frequency energy until thoroughly mixed at least five more times and rapidly cooled. In contrast, samarium alloys only need to be melted once in an aluminum oxide crucible;
from 0 to 1200°C, i.e. about 1 of the respective melting temperature.
Smoky for about 1 hour at a temperature below 50℃. For this purpose, the heating element of the individual alloy is placed on an aluminum oxide base in a closed niobium hollow cylinder that is inductively heated under argon as a protective gas.

After being synthesized and repeatedly melted and solidified, the resulting alloy is initially still in a multiphase state. In this case, in addition to the tetragonal ThMa phase, a rhombohedral ThgZntv phase is also observed together with other phases. On the other hand, the alloy is actually only one phase after the final smoldering to homogenize, with residues of oxides and other phases being observed in amounts of up to 3% by volume in total. In this case, the individual phases of the alloy can be treated metallographically and by radiographic analysis.

FIG. 1 shows the corresponding concentration ratios of the ternary system Fe--Mo--Nd in a generally conventional graph with an isothermal section at about 1200 DEG C. In this case, the corner points are the three alloy components Fe, Mo, and Nd (each with a concentration of 100
Starting from the three sides determined by Each side of the concentration triangle is a binary system M.

The surface of the triangle, which shows the composition of Fe, FeNd and NdMo, is covered with a grid of parallel lines to the three sides, with adjacent parallel lines each having a spacing of 2 atom %. In this figure, only the important Fe angle of the three-component system is shown in detail. As can be read from the drawing, ThMn
The ternary magnetic field to which the phase Nd@FII*JO+* with +m structure belongs is separated by a two-phase magnetic field from the range starting from Nd*Pety with Th1Zn+v structure. This can be determined by examining it using an X-ray diffraction needle.

According to the invention, the magnetic material should have a large amount of phases with a ThMn+* structure. In order to meet this requirement, the amounts of the individual alloying components in the material must be determined from the beginning, i.e., generally the Fe component is 60 to 85 atom%, the R component is 2 to 20 atom%, and the M component is 4 to 35 atom%. Select %.

ThMn+* structure is at least 50% by volume of the present invention material
From the surface of the corresponding concentration triangle, we select a pentagonal subsurface determined by the following five points Pi to P5.

R [atomic%] Iron [atomic%] M [atomic%] Pi
4 65 31P2 4 85
1.1P3 9 85 6P
41579 6 P5 15 65 20 In Figure 1, these five points are the ternary system Nd-Fa-M.

is filled in the concentration triangle of . In this case, the pentagonal surface indicated by the dashed line encompasses the area indicated by the dashed line with the ThMn+* structure, which can be described in more detail by the following points P1 to P5.

Nd (atomic%) Fe (atomic%) Mo (atomic%) PI
7 65 28P2 7
80 13P3 8 E
15 9,5P4 10 78
12P5 10 65 25
The magnetization M in relation to the temperature T is expressed as the type pl! @@MO+
The graph of FIG. 2 shows a magnetically unoriented ternary single-phase alloy according to the invention with fR1, assuming an external magnetic field 10 of ^/CI. 2 Ms-f(T)
Therefore, each Chieri temperature Tc can be determined as the intersection of the straight part of the corresponding curve and the temperature axis. The corresponding confirmation values are obtained from the following table. This table also shows the saturation magnetization Ms of the individual alloys at room temperature and in an external magnetic field of 70 kOe.
The saturation magnetization, Ms, is measured, for example, using a vibrating magnetic needle with a corresponding plastic-bonded magnetically oriented powder.

Rare earth component RTc ('C) Ms (T)Ce
85 0.65Nd
l B 5. 1.03Nm 202
0.97Cd 205 0,
67Dy 142 0.60E r
108 0.65 The Chieri temperature Tc listed in the table above is the same as the rare earth component R in Figure 3.
is shown in contrast to the Chieri temperature of a known ternary alloy of type F6+tRJ with In this case, the known alloys are from the literature [
Proceedings of the 8th International Conference on Rare Earth Magnets tlil (Pro
c, 8th Int.

11orkshop on Rare-Earth-M
Agnets) J Dayton Inc. Ohio (USA)
Published in 1985, pages 423-44G.

Similarly to the drawing according to FIG. 3, in FIG.
On Rare-Earth-Magnets), the saturation magnetization Ms of the alloy Pe+aRmB is compared.

As is clear from both Fig. 3 and Fig. 4, the phase Fe@
eMO+Js has a Chieri temperature Tc within a range of approximately 100 to 200°C and a saturation magnetization Ms within a range of approximately 0.6 to IT.
has. In this case, the course of the individual values in the series of rare earth metals R corresponds to that of the known type Pel4RtB. The highest Chieri temperature exists in the gadolinium phase and the highest saturation magnetization in the neodymium phase.

Typical phases with light rare earth metals in which ferromagnetic coupling between R and Fe moments can be expected have higher saturation magnetization than phases with heavy rare earth metals.

In this case P6soMO+*S11 key and F6*eMO+
*Gds has particularly remarkable magnetic anisotropy in the samarium phase.

According to the above examples, the material R-Fe-M according to the invention
The starting point was one in which the M component was the element MO. However, a corresponding relationship also occurs if this metal of the chromium group is at least partially replaced by tungsten (W) metal.

Furthermore, a ternary alloy was selected for the embodiment according to the invention.

However, in addition to the above-mentioned Otai gold component, the material according to the invention may also contain at least one other alloying component in an amount of up to 1 atomic %, i.e. preferably up to 8 atomic % for Nd and Sm alloys. % of cobalt (Co) can be alloyed to increase the Curie temperature and/or saturation magnetization.

In this case, a CO acid component is added in place of a corresponding amount of Fe component. Obtained quaternary alloy Nd5F11v*C01M
01° is, for example, a ternary alloy NdsFes that does not contain Co.
tMOt.

Curie temperature is about 100℃ higher than that of about 0.3℃.
T has increased saturation magnetization.

Suitable starting materials for hard magnetic materials are ternary phases with Sm and Sm and C due to their high crystal anisotropy.

Of particular interest are image component phases having . In this case, the anisotropic magnetic field strength reaches approximately 90 kOe.

It is also advantageous for the materials according to the invention with three or more alloying components to be used not only in pure form, but rather as components of mixtures or composites. For example, they can be incorporated into or laminated to inorganic materials, such as glasses or ceramics, AhOs, SiC or B, as well as organic materials.

[Brief explanation of the drawing]

Figure 1 is a graph showing a part of the isothermal cross section in the ternary system Fe-Mo-Nd, and Figure 2 is a graph of a special Fe1M0
Magnetization curve diagrams in relation to the temperature of the +IR* alloy, Figures 3 and 4 show the Curie temperature and saturation magnetization of the Fe50M0+*Rs alloy in comparison with the known materials Fe, RJ. The graph diagram, FIG. 5, shows the known binary compound MoBe.
It is a schematic diagram showing the structure of +t. IG 5 T [@C1---- I32

Claims (1)

[Claims] 1) It has at least three alloy components R, iron (Fe) and M, the material content of the iron component is at least 60 atomic %, and a tetragonal ThMn_1_2 structure is formed in the material. In the iron-containing magnetic material, a) R is at least one element selected from the group of rare earth metals, M is molybdenum (Mo) and/or tungsten (W), and b) the Fe content is c) the content of R is between 2 and 20 at %; d) the content of molybdenum and/or tungsten is between 4 and 3;
An iron-containing magnetic material characterized by an iron content of 5 at.%. 2) When the concentration ratio of the ternary system R-Fe-M is expressed graphically as a triangular plane having corner points formed by each component using a method known per se, the following points P1, P2, P
3, P4 and P5: R [atomic %] iron [atomic %] M [M-%] P1 4 65 31 P2 4 85 11 P3 9 85 6 P4 15 79 6 P5 15 65 20 On the plane of the pentagon defined by 2. Material according to claim 1, characterized in that the contents of the three alloying components are selected such that an intersection point located at is obtained. 3) Material according to claim 1 or 2, characterized in that the iron content is at most 82 at.%. 4) The material according to claim 1, characterized in that, in addition to the phase having the ThMn_1_2 structure, at least another phase of the R-Fe-M system is present. 5) Material according to claim 1, characterized in that, in addition to the three alloying components R, Fe and M, it also has at least one other alloying component. 6) Material according to claim 5, characterized in that the amount of another alloying component is at most 10 atomic %. 7) The material according to claim 5 or 6, characterized in that it contains cobalt (Co) as another component in a maximum amount of 8 at %, and a corresponding amount of iron component is removed. 8) Material according to one of claims 1 to 7, characterized in that the R component consists of at least two rare earth metals. 9) Material according to one of claims 1 to 8, characterized in that it is embedded in or laminated to another material. 10) The material according to claim 9, characterized in that the constituent components are mixed materials or composite materials.