Theoretical study of the rare-earth compounds Nd2Co17$minus;xTx (T = Fe, Cr), and Nd2(Co1$minus;xFex)17$minus;yCry

Abstract

The phase stabilities of the intermetallics Nd 2 Co 17− x T x (T = Fe, Cr), and Nd 2 (Co 1− x Fe x ) 17− y Cr y are tested by including random atom shift, global deformation and high temperature disturbance under control of the pair potentials. The ternary elements T substitute for Co without changing the crystal symmetry and preferentially occupy the 6c site. The calculated structural parameters correspond well to the experimental data. The variation behavior of the Curie temperature of Nd 2 Co 17− x Fe x and Nd 2 (Co 1− x Fe x ) 17− y Cr y is explained qualitatively by the exchange interaction model. All these prove the effectiveness of ab initio pair potentials obtained through the lattice inversion method in the description of rare-earth materials.