Open AccessConventional and Inverse Magnetocaloric Effect in Ni-Rich Ni-Mn-Ga and Ni-Mn-Sn Heusler Alloy: A Comparison
Author(s) -
Dulal Pal
Publication year - 2020
Publication title -
journal of scientific research
Language(s) - English
Resource type - Journals
eISSN - 2070-0245
pISSN - 2070-0237
DOI - 10.3329/jsr.v12i3.44357
Subject(s) - magnetic refrigeration , materials science , austenite , alloy , magnetization , magnetic shape memory alloy , martensite , condensed matter physics , metallurgy , inverse , atmospheric temperature range , magnetic field , magnetic anisotropy , microstructure , thermodynamics , physics , geometry , mathematics , quantum mechanics
Magnetic and magnetocaloric effect of Ni-rich Ni52Mn34Sn14 (Ni-Mn-Sn) and Ni54Mn17Ga29 (Ni-Mn-Ga) Heusler alloys have been investigated up to a magnetic field of 5T and within a temperature range of 4.2 – 325 K. In this study, we report a systematic comparison between Ni-rich Ni52Mn34Sn14 and Ni54Mn17Ga29 alloys in the light of their magnetocaloric effect (MCE). In both the samples, a large magnetic entropy change was observed (~96 J kg-1 K-1 for Ni-Mn-Ga), but for the alloy Ni-Mn-Sn the MCE becomes negative/inverse. From various magnetic measurements it have been observed that in Ni-Mn-Sn alloy the martensite to austenite transition accompanied by lower to higher magnetization whereas for Ni-Mn-Ga alloy reverse situation occurred. The different type of magnetocaloric effect, i.e. inverse and direct can be explained by considering magneto-crystalline anisotropy and different state of magnetization of the martensite and austenite phase of the alloys.