Electronic structure and ferromagnetism in the martensitic-transformation materialNi2FeGa

Z. H. Liu, H. N. Hu, G. D. Liu, Y. T. Cui, M. Zhang, J. L. Chen, G. H. Wu, Gang Xiao
2004 Physical Review B  
We calculated the electronic structures of the Heusler alloy Ni 2 FeGa for both the cubic and the orthorhombic structures by self-consistent full-potential linearized-augmented plane-wave method. The localized moment of Fe atom is interpreted based on the electronic structure and the popular explanation of the localized moment of Mn in Heusler alloy X 2 MnY . Comparing the density of states of cubic and orthorhombic structures, we observed that a Ni peak near the density of states of d band for
more » ... the cubic structure splits for the orthorhombic structure, indicating a band Jahn-Teller mechanism should be responsible for the structural transition. Accompanied by this transformation, an increase of Ni moment and magnetization redistribution occurred. Temperature-dependence anisotropy field shows an evidence of martensitic transformation between 125 and 190 K. The magnetic behavior seems to contain a transition from Heisenberg-like at temperature below 70 K to itinerant magnetism at temperature higher than 160 K upon martensitic transformation. Temperature dependence of saturation magnetization reveals the spontaneous magnetization at martensite and parent phase are 3.170 B and 3.035 B , respectively. The calculated magnetic moment at martensite is 3.171 B , which is quite consistent with the experimental value. The magnetic moment of Fe and Ni atom in Heusler alloy Ni 2 FeGa is analyzed based on the computational results and the experimental magnetization curves. It is found that the magnetic moment of Fe atoms is about 10-43% larger than that of ␣-Fe.
doi:10.1103/physrevb.69.134415 fatcat:en7bjvkgpvfyvnumra2clkwfvy