Magnetism and electronic band properties of NiFeMnAl Heusler alloy

Heusler alloys exhibiting half-metallic or spin gapless semiconducting (SGS) properties have become attractive materials for spin-transport-based devices. This is due to their ability to have tunable magnetic properties and high Curie temperatures well above room temperature. We have investigated one such material, NiFeMnAl, which is predicted to show SGS properties. We have synthesized NiFeMnAl alloy using arc-melting in an argon environment. X-ray diffraction patterns indicate that the as-prepared sample has a single-phase cubic crystal structure with disorder. The isothermal magnetization measurement M(H) carried out at 100 K shows a saturation magnetization of about 54 emu/g. The thermomagnetic M(T) measurement shows that there is a single magnetic transition at its Curie temperature of about 460 K. We will also discuss the effect of heat treatment and the results of first principles calculations.