Structure and anisotropic compensation of Tb_(1-x)Pr_x(Fe_(0.4)Co_(0.55)B_(0.05))_(1.93) (0 = x = 1) magnetostrictive alloys

摘要

Structural, magnetic and magnetostrictive properties of Tb_(1-x)Pr_x(Fe_(0.4)Co_(0.55)B_(0.05))_(1.93) (0 < = x < = 1) alloys have been investigated. The (Tb,Pr)(Fe,Co,B)_2 compounds are found to stabilize in a cubic Laves-phase structure. The lattice parameter increases with increasing Pr content and obeys the linear Vegard's law. The spin phase diagram for the compounds is constructed to illustrate both the composition dependence of the Curie temperature (T_C) and spin reorientation temperature (T_(SR)) and the arrangement for the easy magnetization direction (EMD). It is found that T_C decreases, while T_(SR) increases as increasing Pr content. The saturation magnetization (M_s) decreases to reach a minimum when x < = 0.50, and then increases with further increasing Pr content. The composition for magnetic-moment compensation is about x_(comp) = 0.55. The magnetostriction (lambda_a) decreases with increasing Pr content when 0< = x < = 0.50, then increases with a further increasing x and exhibits a peak in the range of 0.50 < = x < = 1.0. Both the magnetization and the magnetostriction analyses show that Tb_(1-x)Pr_x(Fe_(0.4)Co_(0.55)B_(0.05))_(1.93) is an anisotropy compensation system and the compensation point is close to x= 0.80.