Magnetic and Magnetocaloric Properties of NiFeMnGa_0.5Sn_0.5 Heusler Alloy

Heusler alloys have attracted recent attention because of their multiple interesting properties with prospects for spintronics, energy technology and magnetic refrigeration. Additionally, the magnetic properties of these materials can be tuned to fit specific applications by adjusting the elemental composition. Here, we present our investigation on how the structural order and magnetic properties of a Heusler alloy NiFeMnGa can be modified by replacing a fraction of Ga with Sn. We have investigated NiFeMnGa_0.5Sn_0.5 alloy prepared by arc melting and annealing. The samples show highly ordered cubic LiPdMnSn-type crystal structure. The samples are ferromagnetic at room temperature with the Curie temperature of 336 K. The high-field (3T) magnetization at 100 K is 61 emu/g. We will discuss the effect of nanostructuring and heat treatment on the structural, magnetic, and magnetocaloric properties of this material. We will also present the first-principle results of the band structure and magnetic properties and compare them with the observed experimental data.