Site preference and structural transition of R(Ni, M)5 (R = La, Nd, Gd), (M = Al, Fe, Co, Cu, Mn)

The phase stability, structural parameter, site preference of R(Ni, M)(5) (R = La, Nd) and structural transition of RNi5-xAlx (R = Nd, Gd) have been studied by using a series of interatomic potentials acquired by lattice inversion method. The calculated lattice parameters are found in good agreement with the values deduced from experiments. The calculated results show that the M (M = Al, Fe, Co, Mn) atoms preferentially occupy the 3g site; the Cu atoms prefer the 2c site and the structure of RNi5-xAlx (R = Nd, Gd) will transfer from CaCu5 structure to HoNi2.6Ga2.4 structure for high aluminum content. (C) 2004 Elsevier B.V. All rights reserved.