Enhanced magnetocaloric effect in Ni-Mn-Sn-Co alloys with two successive magnetostructural transformations.

ABSTRACT: High magnetocaloric refrigeration performance requires large magnetic entropy change ?S M and broad working temperature span ?T FWHM . A fourth element doping of Co in ternary Ni-Mn-Sn alloy may significantly enhance the saturation magnetization of the alloy and thus enhance the ?S M . Here, the effects of Co-doping on the martensite transformation, magnetic properties and magnetocaloric effects (MCE) of quaternary Ni47-xMn43Sn10Cox (x?=?0, 6, 11) alloys were investigated. The martensite transformation temperatures decrease while austenite Curie point increases with Co content increasing to x?=?6 and 11, thus broadening the temperature window for a high magnetization austenite (13.5, 91.7 and 109.1?A·m2/kg for x?=?0, 6 and 11, respectively). Two successive magnetostructural transformations (A???10?M and A???10?M?+?6?M) occur in the alloy x?=?6, which are responsible for the giant magnetic entropy change ?S M?=? 29.5?J/kg·K, wide working temperature span ?T FWHM ?=?14?K and large effective refrigeration capacity RC eff ?=?232?J/kg under a magnetic field of 5.0?T. These results suggest that Ni40.6Mn43.3Sn10.0Co6.1 alloy may act as a potential solid-state magnetic refrigerant working at room temperature.

SUBMITTER: Zhang X 

PROVIDER: S-EPMC5974186 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature