Formation of Compounds and Their Magnetic Properties of Rapidly Quenched (Fe1-xCox)4.5(Ni,Al)0.5Sm Alloys

The formation and magnetic properties of CaCu5-, Th2Zn17- and PuNi3-type compounds in (Fe1-xCox)4.5Al0.5Sm and (Fe1-xCox)4.5Ni0.5Sm alloys, rapid-quenched at disk velocities ranging from 8.4 to 41.9 m/s, were investigated. The CaCu5-type (Fe1-xCox)4.5 (Ni,Al)0.5SM compounds were formed in the composition range 0.6¿×¿1.0 The formation range is the same as when Al and Ni are not added. The difference resulting from addition of Al and Ni is that CaCu5-type compounds can be formed at lower disk velocities, indicating 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 (Fe1-xCox)17Sm2Al¿ and (Fe1-x Cox)17Sm2Ni¿ (x¿0.6) compounds increases by 2 to 4% and by 1 to 2% respectively. The particularly large increase in the unit cell volume of the former is believed to raise the Curie temperature and the coercivity.