Effects of Co substitution for Fe on the structural and magnetostrictive properties of melt-spun Tb0.2Nd0.8Fe1.9 ribbons

A series of Tb0.2Nd0.8(Fe1−xCox)1.9(0.0⩽x⩽0.4) Laves ribbons were prepared by arc-melting and subsequent melt-spinning technique. The effects of Co substitution for Fe on the structural and magnetostrictive properties of Tb0.2Nd0.8Fe1.9 ribbons were investigated. Tb0.2Nd0.8Fe1.9 ribbons consist of (Tb,Nd) Fe2 Laves phase and a minor of rare earth but free of (Tb,Nd) Fe3 phase. Almost single Laves ribbons can be obtained when x⩾0.1, which indicates that the Co substitution for Fe is beneficial for the formation of Laves ribbons. The lattice parameter of the Laves ribbons decreases with increasing x. The Curie temperature of the Laves phase and saturation magnetization of the ribbons both get maximum at x = 0.2. Meanwhile, the magnetostriction Tb0.2Nd0.8Fe1.9 ribbons can be improved by a proper amount of substitution of Co for Fe.