Magnetic transitions and magnetostrictive properties of Laves compounds Sm0.88Nd0.12(Fe1−xCox)1.93

The structure, magnetic and magnetostrictive properties of Sm0.88Nd0.12(Fe1−xCox)1.93 (0≤x≤1.0) alloys have been investigated. The alloys have the cubic MgCu2 structure over the whole composition range and the lattice parameter a decreases with increasing x. For 0≤x≤0.2, substitution of Co for Fe slightly increases the saturation magnetization Ms and Curie temperature Tc, while further substitution causes a decrease in both Ms and Tc. The spin reorientation is observed, and a phase diagram for the spin configurations of the Sm0.88Nd0.12(Fe1−xCox)1.93 system is determined. The spontaneous magnetostriction λ111 increases as x is increased, while a monotonic decrease of the saturation magnetostriction λs with x originates from the increase of λ100 with opposite sign to that of λ111, which may be caused by the filling of the d band due to Co substitution.