Magnetocaloric effect and magnetoelastic properties of NiMnGa and NiMnSn Heusler alloy thin films

Series of NiMnSn and NiMnGa Heusler alloys thin films of different compositions were obtained by DC magnetron sputtering in order to achieve strong magnetocaloric effect in the temperature range close to the room temperature. The maximal magnetocaloric effect was found in the temperature range 320-350 K, with the maximal entropy change -ΔS ranges from 1.4×104 erg/gK to 2.7×104 erg/gK. Strain modulated ferromagnetic resonance technique was used to determine magnetoelastic properties of the films. Magnetoelastic constants of an order of 106 erg/cm3 were found.