Phase transition processes and magnetocaloric effects in the Heusler alloys NiMnGa with concurrence of magnetic and structural phase transition

• DOI: 10.1063/1.1991995
• Publication Date: 2005-08-16T22:01:50Z
• Authors: Y. Long; Z. Y. Zhang; D. Wen; G. H. Wu; R. C. Ye; Y. Q. Chang; F. R. Wan
• Keywords: Magnetic refrigeration; Magnetic shape-memory alloy

The Ni2MnGa-based Heusler alloys with high magnetocaloric effect have attracted considerable attention as a promising magnetic refrigerant. phase-transition processes and entropy changes in the NiMnGa concurrence of structural phase transitions were studied. ac susceptibility results showed transition occurred during reverse martensitic Ni55.5Mn20Ga24.5 alloy direct from ferromagnetic matrensitic to paramagnetic austenitic Ni54.9Mn20.5Ga24.6 alloy. When field had changed 2 T, comparable large change was observed both alloys, which is speculated result discontinuous magnetization near transition.