Ab initio investigation of the structural and magnetic properties of Ni-Pt-Mn-Ga alloys

Abstract

Structural and magnetic properties of Ni2-xPtxMnGa alloys are investigated from first principles calculations with the help of the spin-polarized relativistic Korringa-Kohn-Rostoker and Plane-Wave Self-Consistent Field methods. The atomic chemical disorder at specific site has been implemented using coherent potential approximation. Calculated equilibrium lattice parameters are in a good agreement with experimental data and other theoretical calculations. The composition dependences of the magnetic exchange couplings and the Curie temperature for cubic phase are obtained. Our calculations have shown that an increase content of Pt results to decrease of magnetic interactions between Mn atoms and to change of interaction sign from ferromagnetic type to antiferromagnetic one for composition Ni 1.0Pt1.0MnGa. Calculated Curie temperatures are in an agreement with experimental data. © 2013 Materials Research Society.