Effect of exchange interaction on spin reorientation in theNd2Fe14B system

Spin reorientation in ${\mathrm{Nd}}_2$(${\mathrm{Fe}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{T}}_{\mathrm{x}}$ ${)}_{14}$B (T=Al, Si, Ti, Cr, Mn, Co, Ni, and Cu) with x=0.05 and 0.10 was investigated. The substitution of Fe by T results in a decrease of spin reorientation temperature ($T_{\mathrm{SR})}$. The effect on $T_{\mathrm{SR}}$ of the substitution by Al, Si, Cr, or Mn is much higher than that of the substitution of Nd by other rare-earth element. Theoretical analyses showed that the changes in anisotropies of the 3d sublattice have little effect on $T_{\mathrm{SR}}$. The changes in R-Fe exchange interactions alone account for this behavior.