Mn substitution effect on magnetostriction temperature dependence in Tb_0.3Dy_0.7Fe₂

Magnetostriction temperature dependencies in Tb_0.3Dy _0.7 (Fe_1-xMn_x)₂ were investigated. Mn substitution lowers the spin reorientation temperature, at which magnetostriction shows a sharp drop. Moreover, Mn containing compounds show larger magnetostriction than that for a Mn-free compound at low temperature. Mössbauer measurements show that easy magnetization direction for the Mn containing compound is in the 〈111〉 direction at 300 K, while it is in the 〈100〉 at 77 K. These results indicate that the tetragonal distortion λ₁₀₀ increases by Mn addition in Tb _0.3Dy_0.7Fe₂.