Secondary particles for anisotropic magnetic powder and method of producing anisotropic magnetic powder
Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.
1. A method of producing an anisotropic magnetic powder, comprising:
obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from the group consisting of Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu;
obtaining a second precipitate containing R and iron and titanium by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron without titanium;
obtaining an oxide containing R, iron, and titanium by calcining the second precipitate;
obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere;
obtaining alloy particles by reducing the partial oxide; and
obtaining an anisotropic magnetic powder by nitriding the alloy particles.
2. The method of producing an anisotropic magnetic powder according to claim 1 ,
wherein the solution containing R, iron, and titanium used in the step of obtaining the first precipitate containing R, iron, and titanium, and the solution containing R and iron without titanium used in the step of obtaining the second precipitate containing R and iron and titanium each further contain tungsten.
3. The method of producing an anisotropic magnetic powder according to claim 1 ,
wherein the solution containing R, iron, and titanium used in the step of obtaining the first precipitate containing R, iron, and titanium, and the solution containing R and iron without titanium used in the step of obtaining the second precipitate containing R and iron and titanium each further contain lanthanum.
4. The method of producing an anisotropic magnetic powder according to claim 1 ,
wherein the anisotropic magnetic powder is represented by the following formula:
R v-x Fe (100-v-w-t-z) N w Ti t La x W z
wherein R is at least one selected from the group consisting of Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; 3≤v≤30; 5≤w≤15; 0<t≤1.0; 0≤x≤1.0; and 0≤z≤2.5.
5. The method of producing an anisotropic magnetic powder according to claim 1 ,
wherein R is Sm.
6. The method of producing an anisotropic magnetic powder according to claim 2 ,
wherein the solution containing R, iron, and titanium used in the step of obtaining the first precipitate containing R, iron, and titanium, and the solution containing R and iron without titanium used in the step of obtaining the second precipitate containing R and iron and titanium each further contain lanthanum.
7. The method of producing an anisotropic magnetic powder according to claim 2 ,
wherein the anisotropic magnetic powder is represented by the following formula:
R v-x Fe (100-v-w-t-z) N w Ti t La x W z
wherein R is at least one selected from the group consisting of Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; 3≤v≤30; 5≤w≤15; 0<t≤1.0; 0≤x≤1.0; and 0≤z≤2.5.
8. The method of producing an anisotropic magnetic powder according to claim 2 ,
wherein R is Sm.
9. The method of producing an anisotropic magnetic powder according to claim 3 ,
wherein the anisotropic magnetic powder is represented by the following formula:
R v-x Fe (100-v-w-t-z) N w Ti t La x W z
wherein R is at least one selected from the group consisting of Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; 3≤v≤30; 5≤w≤15; 0<t≤1.0; 0≤x≤1.0; and 0≤z≤2.5.
10. The method of producing an anisotropic magnetic powder according to claim 3 ,
wherein R is Sm.
11. The method of producing an anisotropic magnetic powder according to claim 4 ,
wherein R is Sm.