Influence of Ni doping on the electronic structure of Ni₂MnGa

The modifications in the electronic structure of Ni_2+xMn_1−xGa by Ni doping have been studied using the full potential linearized augmented plane wave method and ultraviolet photoemission spectroscopy. Ni 3d-related electron states appear due to formation of Ni clusters. We show the possibility of changing the minority-spin density of states (DOS) with Ni doping, while the majority-spin DOS remains almost unchanged. The total magnetic moment decreases with excess Ni. The total energy calculations corroborate the experimentally reported changes in the Curie temperature and the martensitic transition temperature with x.