The structure and hard magnetic properties of rapidly quenched (Sm, Zr)1(Fe, Si)12 alloys

The influence of partial substitution of zirconium for samarium on the phase composition of cast (Sm 1-x Zr x ) 1+δ Fe 10-δ Si 2 alloys and the influence of the quenching rate and annealing temperature on the microstructure and magnetic properties of rapidly quenched (Sm 0.7 Zr 0.3 ) 1+δ Fe 10-δ Si 2 ribbons were investigated. Upon the substitution of zirconium for samarium, the uniaxial anisotropic (Sm,Zr) 1 Fe 10 Si 2 phase with a ThMn 12 -type structure is formed directly during the solidification of the ingot. The amorphous phase, which is formed in the rapidly quenched ribbons, initially crystallizes into a metastable phase of the TbCu 7 type. The phase with a ThMn 12 -type structure is formed at temperatures of 900-1000°C. Annealing of ribbons at such high temperatures is accompanied by evaporation of Sm and coarsening of the grain structure, which does not permit the translation of the strong magnetic anisotropy of the (Sm,Zr) 1 Fe 10 Si 2 phase into high values of the coercive force.