Effect of composition and hydrostatic pressure on the magnetocaloric properties of Pt doped Ni2MnGa Heusler alloy

摘要

The magnetocaloric effect on Ni2-xPtxMnGa (x= 0.2, 0.3 and 1.0) shapememory Heusler alloy around martensite transformation temperature (TM) is investigated. Themagnetic entropy (ΔSm) decreases marginally with increasing Pt content at Ni site in Ni2MnGa forvarious external applied magnetic field up to 3 T. The effect of hydrostatic on ΔSm for x = 0.2 i.eNi1.8Pt0.2MnGa is also investigated. We observed that the application of hydrostatic pressure increasesthe martensite phase transition temperature (TM) and therefore pressure stabilizes the martensitephase for Ni1.8Pt0.2MnGa with a rate of 0.4 K/ GPa, while with increasing pressure, the ΔSm isdecreases.