Atomistic simulation for the phase stability and site preference of R₃(Fe,T)₂₉(R = Nd,Gd,Y; T = Ta,W)

Abstract

The phase stability and site preference of the intermetallics R 3 (Fe, T) 29 (R = Nd, Gd, Y; T = Ta, W) with Nd 3 (Fe, Ti) 29 structure have been investigated by lattice inversion potentials. The calculated results indicate that each of the stabilizing elements Ta and W significantly decreases the cohesive energy of R 3 (Fe, T) 29 and plays a role in stabilizing the 3:29 structure. Among the 11 different kinds of Fe sites in these compounds the preferential sites of Ta and W are 4i 3 , 4i 4 and 4g sites. The calculated lattice parameters of R 3 (Fe, T) 29 compounds are in good agreement with the experimental data. The structural stability of the R 3 (Fe, T) 29 compounds is further tested at different temperatures. Based on the pair potential curves an intuitive explanation for the phase stability and solubility is made.