Magnetic entropy change of V substituted Ni-Mn-Ga Heusler alloy

Abstract

The magnetization behaviors have been analyzed for Ni54Mn21-xVxGa25 (x=0,2,4) alloys which were prepared by conventional arc melting method in argon atmosphere. The Curie temperature T-C was found to be 325, 300, and 265 K and the austenitic transition temperature T-A on heating was found to be 315, 217, and 124 K for x=0, 2, and 4, respectively. The magnetic characteristics were performed with a Quantum Design superconducting quantum interference device magnetometer in the field of up to 20 kOe. A large magnetic entropy change Delta S-M, which is calculated from H versus M curves associated with the ferromagnetic-paramagnetic transitions, has been observed. The maximum Delta S-M for an applied field of 2.0 T is 2.49, 1.92, and 1.81 J/kg K for x= 0, 2, and 4, respectively. (c) 2009 American Institute of Physics. [DOI: 10.1063/1.3072819]