Comparative Study of Electronic Structure in Ferromagnetic Heusler Alloys Ni₂MnX (X = Al, Ga, In) Using the Quasi-Particle Self-Consistent GW Method

Abstract

  A comparative study of cubic Heusler alloys Ni₂MnX (X = Al, Ga, In) was performed to explain the differences in material properties using a first-principles electronic structure calculation of quasi-particle self-consistent GW (QSGW) method. The obtained electronic structures indicate a similar density of states (DOS) of Ni 3d e_g orbitals on the Fermi level for all the studied materials, implying a promotion to a band Jahn-Teller (BJT) distortion. The generalized susceptibility analysis suggests some instability of the cubic high symmetry phase and indicates, that the Ga containing material is the one which is the most pronounced to 10M modulation due to this instability. Taking the advantage of accurate first-principles electronic structure calculations performed by QSGW, the U parameters of Hubbard correction on Mn and Ni atoms were determined using the density functional theory (DFT) approach with generalized gradient approximation (GGA), so that the local and total QSGW magnetic moments are reproduced.