Effect of electron localization in theoretical design of Ni-Mn-Ga based magnetic shape memory alloys

The precise determination of the stability different martensitic phases is an essential task in successful design (magnetic) shape memory alloys. We evaluate effect electron delocalization correction on predictive power density functional theory for Ni-Mn-Ga, prototype magnetic compound. Using corrected Hubbard-model-based generalized gradient approximation (GGA+U), we varied Coulomb repulsion parameter U from 0 eV to 3 reveal evolution predicted material parameters. increasing localization Mn sites results stabilization 10M modulated structure stoichiometric Ni2MnGa agreement with experiment whereas uncorrected GGA and meta-GGA provide lowest energy 4O non-modulated structure, respectively. GGA+U calculations indicate that more stable than other structures > 1.2 eV. key features states (DOS) responsible or destabilization particular calculated are found also DOS advanced quasi-particle self-consistent GW (QSGW) method. It supports physical background Hubbard correction. Moreover, = 1.8 best experimental data lattice parameters off-stoichiometric