LAUSR

Abstract Our previous Mossbauer studies have shown that the A1 to L10 structural transformation in equiatomic FePd is a complex transformation of the cascade type. The FePd ordering involves more phases that one may expect. In addition to the ordered L10 phase it can proceed via the cubic ordered L12 (Pm-3m) phase and intermediate low-symmetry phases, namely the disordered tetragonal phase A6 (I4/mmm), the modified L10* phase (P4/mmm), the ordered hexagonal Fe2Pd and FePd2 (P-3m1), the ordered tetragonal FePd2 (I4/mmm) and probably, the orthorhombic 5:3 (Cmmm) phases. We theoretically investigate the phase stability of proposed phases using first principle density functional calculations. Structurally, tetragonal L10* modified, cubic FePd3, tetragonal FePd2 and orthorhombic Fe3Pd5 are energetically stable and likely to form in the course of the A1 to L10 structural transformation. All these phases show interesting magnetic properties. We report magnetization, Curie temperature and magnetocrystalline anisotropy of these phases.