Atomistic simulation for the phase stability, site preference and thermal expansion of YFe_(12-x)T_x (T = Ti, V, Cr, Mn, Zr, Nb, Mo, W)

摘要

The effect of the ternary element on the structural properties of YFe_(12-x)T_x (T = Ti, V, Cr, Mn, Zr, Nb, Mo, W) has been studied by using interatomic pair potentials based on ab initio method and lattice inversion equations. Calculated results show that adding ternary element T makes the crystal cohesive energy of YFe_(12-x)T_x decrease markedly, which indicates that T helps stabilize the 1:12 phases. The ternary elements T prefer to occupy the 8i sites in these compounds. The calculated results are found in good agreement with the values deduced from experiments. Furthermore, we have calculated the thermal expansion of YFe_(11) V compounds with the ThMn_(12) structure. The method utilized in the present investigation offers a rather casy and direct way to study the structural properties of YFe_(12-x)T_x.