Competition of single-ion anisotropy of Sm and Dy ions during the spin-reorientation transition in (Nd1–x–ySmxDyy)(FeCo)B supermagnets

Abstract

It has been found that an increase in the Sm concentration in the range x = 0.05–0.18 in (Nd_1‒x‒ySm_xDy_y)(FeCo)B supermagnets leads to a shift in the spin-reorientation transition temperature to higher values, whereas a Dy addition results in a decrease in the transition temperature. Single-ion anisotropy of Sm and Dy ions has different symmetry, making contributions of opposite signs to the resulting magnetic anisotropy of the lattice. Therefore, the threshold temperature T_S of the spin-reorientation transition, which is determined by the balance of magnetic anisotropies of sublattices, can be controlled using ions with different symmetries.