Magnetocaloric effect and magnetic-field-induced shape recovery effect at room temperature in ferromagnetic Heusler alloy Ni–Mn–Sb

The martensitic transition, magnetocaloric effect (MCE) and shape memory effect (MSE) of ferromagnetic Heusler alloys Ni 50 Mn 50− x Sb x ( x = 12, 13 and 14) have been investigated. A large positive magnetic entropy change Δ S M was observed in the vicinity of the martensitic transition. The maximum value of Δ S M is 9.1 J kg −1 K −1 in Ni 50 Mn 37 Sb 13 at 287 K for a magnetic field change of 5 T. This change originates from the first-order transition from a low-temperature weak-magnetic martensitic phase to a high-temperature ferromagnetic parent phase. A magnetic-field-induced shape recovery strain of about 15 ppm at room temperature and at a relatively low magnetic field (1.2 T) was observed to accompany the reverse martensitic transformation. The large field-induced MCE and MSE in the NiMnSb system make it a promising material for room-temperature application.