Dopant effects on martensitic transition and magnetic properties of Ni51.5Mn25Ga23.5 materials

Abstract

Ni51.5Mn23M2Ga23.5 materials are to reveal the dopant effect on the martensitic transition and the magnetic propert ies. We found that the dopants Ti, Zr, Hf, V, Nb, and Ta lower the martensitic transition temperature of the sample, but W increases it. The martensitic trans ition temperature is very sensitive to the atomic size when the valence electron ic concentration keeps constant for the doping elements. The dopants Ti, Zr, Hf or V decrease the magnetic moment of Mn atom in the martensite at low temperatur e, while Nb, Ta or W enhance it. A corresponding variation of TC of t he materials is not observed, which indicates that the influence of the lattice change of martensitic transition on the magnetic properties should also be ta lken into account.