Structure and magnetism of pseudo-binary ordered alloys Fe(Rh,Pd), Mn(Rh,Pd), (Fe,Mn)Rh and (Fe,Mn)Pd

Abstract Electronic structures for pseudo-binary ordered alloys Fe(Rh,Pd), Mn(Rh,Pd), (Fe,Mn)Rh and (Fe,Mn)Pd with CuAu-I type structure are calculated by a linear muffin-tin orbital with the atomic sphere approximation and by the generalized gradient approximation. A virtual atom approximation for (Rh,Pd) and (Fe,Mn) is adopted. From the minimum of the total energy, the magnetic state and the equilibrium lattice constants a and c are obtained. It is pointed out that ( Fe 1 - x Mn x ) Rh near x = 0.55 is a good candidate for magnetostrictive and magnetocaloric materials, as a large volume change is expected at the boundary between ferromagnetic and antiferromagnetic states, associated with the martensitic transformation from the CsCl-type structure to the CuAu-I type one.