Influence of austenite ferromagnetism on the elastocaloric effect in a Ni_(44.9)Co_(4.9)Mn_(36.9)In_(13.3) metamagnetic shape memory alloy

摘要

We demonstrate the temperature dependent elastocaloric effect in a Ni44.9Co4.9Mn36.9In13.3 polycrystalline alloy with a strong 001(A) preferred orientation. It is found that the adiabatic temperature changes induced by the compressive stress increase with the increase in testing temperature. The giant adiabatic temperature change up to 14.7K is achieved on loading at 390K, which is much higher than that around room temperature. Such a temperature enhanced effect is attributed to the reduced magnetic contribution to the transformation entropy through narrowing the temperature interval between magnetic transition and martensitic transformation controlled by the mechanical stress.