Exploration of Magnetic Entropy Change Across the Martensite Transformation to Ni_(44)Co_2Mn_(43)ln_(11) Alloy

摘要

The magnetic entropy change (Delta S-M) of Co-doped, Mn-rich Ni46Mn43In11 alloy was investigated using different measurement protocols. The critical magnetic field (H-C) required to induce the austenite phase was found to decay exponentially with temperatures. The field-induced austenite causing a huge change in magnetism across the martensite transformation (MT) was found to contribute to the enhancement of Delta S-M across the MT. Delta S-M across the MT and the Curie temperature (T-C(A)) of the austenite phase was found to have large values of 16.4 J/kg-K and -4.8 J/kg-K for magnetic field change (Delta H) of 50 kOe, at T = 300 K and 363 K respectively. The strong ferromagnetism (FM) of the austenite phase leading to the observed behaviour is comprehensively discussed.