Formation of Compounds and Their Magnetic Properties of Rapidly Quenched (Fe_1-xCo_x)_4.5(Ni, Al)_0.5Sm Alloys

Abstract

The formation and magnetic properties of CaCu₅, Th₂Zn₁₇ and PuNi₃ type compounds were investigated for (Fe_1-xCo_x)_4.5Al_0.5Sm and (Fe_1-xCo_x)_4.5Ni_0.5Sm alloys rapidly-quenched at various disk velocities ranging from 8.4 to 41.9 m/s. The CaCu₅ type (Fe_1-xCo_x)_4.5(Al, Ni)_0.5Sm compounds were formed in the composition range 0.6≤x≤1.0. The formation range is the same as that without addition of Al and Ni. The different point due to the addition of Al and Ni is that the CaCu₅ type compound can be formed at lower disk velocities, indicating the increased stability of the compound. Its unit cell volume does not change with the addition of Al and Ni. On the other hand, the unit cell volume of (Fe_1-xCo_x)₁₇Sm₂Al_δand (Fe_1-xCo_x)₁₇Sm₂Ni_δ(x≤0.6) compounds increases 2∼4% and 1∼2%, respectively. The particular large increase of the unit cell volume of (Fe_1-xCo_x)₁₇Sm₂Al_δ is considered to enhance the Curie temperature and the coercivity.