Large and reversible elastocaloric effect near room temperature in a Ga-doped Ni–Mn–In metamagnetic shape-memory alloy

"We report a giant elastocaloric effect near room temperature in a polycrystalline Ga-doped Ni-Mn-In ferromagnetic shape-memory alloy. The elastocaloric effect has been quantified by measuring both isothermal stress-induced entropy changes and adiabatic stress-induced temperature changes. A reproducible maximum entropy change,Delta S-rev similar or equal to 25 J . K-1 . kg(-1), upon cycling across the martensitic transition was obtained by application of a compressive stress of 100MPa. The corresponding maximum amount of cooling, Delta T-adi similar or equal to -4.9K, was measured when this stress was rapidly removed. These values are comparable with those reported for giant magnetocaloric materials, which are induced by application and release of a high magnetic field. Therefore, the studied material is a good candidate to be used in solid-state refrigeration devices based on the elastocaloric effect.