Electronic structures in magnetic shape memory alloys Fe3X (X=Pd, Pt) by quasi-particle self-consistent GW approach

By means of a state-of-the-art first-principles calculation of quasi-particle selfconsistent GW (QSGW) method, we investigated electronic structures and generalized susceptibilities in cubic Fe3X (X=Pd, Pt) alloys.Compared with those of the density functional method with generalized gradient approximation, the energy band structure indicates both an energy level shift to the high energy side and a narrowing bandwidth in the minority-spin state.Employing the rigid band approximation, the profile of generalized susceptibility was found to indicate the peak positions at = (2/)(1/2,1/2,0) for X=Pd and = (2/)(1/8,1/8,0) for X=Pt to the modulation wave vector.These modulations may be assigned to the instability of the cubic symmetry phase in the martensitic phase transition observed in the experiment.