Hydrostatic pressure effects on martensitic transition, magnetic and magnetocaloric effect in Si doped Ni–Mn–Sn Heusler alloys

• The pressure effects on ΔSM were investigated in Si doped Ni–Mn–Sn alloys.
• The Tm and Curie temperature of the austenitic phase changes with pressure.
• The maximum ΔSM of 24.5 J kg−1 K−1 at 9.7 kbar were observed for x = 1 alloy.
• The RC increases for x = 1 alloy and can be used for magnetic refrigeration.

We report the hydrostatic pressure dependence of martensitic, magnetic and magnetocaloric effect in the Ni48Mn39Sn13−xSix (x = 1 and 4) Heusler alloys. The martensitic transition temperature increased with respect to pressure at the rate of 2.37 K/kbar and 0.7 K/kbar for x = 1 and 4 alloys respectively and decreases with the application of magnetic field at the rate of 1.2 K/T and 0.8 K/T for x = 1 and 4 alloys respectively. The Curie temperature of austenite phase changes marginally under pressure. The maximum magnetic entropy change (ΔSM) of 5.13 J kg−1 K−1 at 0 kbar and 24.5 J kg−1 K−1 at 9.7 kbar were observed for x = 1 alloy. However the magnetic entropy change for x = 4 alloy seems to decrease as a function of pressure.