Progress Report 2011: Understanding compound phase transitions in Heusler alloy giant magnetocaloric materials

Stadler, Shane

关键词: magnetocaloric materials multifunctional materials;   

DOI  :  10.2172/1031031
RP-ID  :  DOE/SC0005295-1
PID  :  OSTI ID: 1031031

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

Our goal is to gain insight into the fundamental physics that is responsible for magnetocaloric effects (MCE) and related properties at the atomic level. We are currently conducting a systematic study on the effects of atomic substitutions in Ni2MnGa-based alloys, and also exploring related full- and half-Heusler alloys, for example Ni-Mn-X (X=In, Sn, Sb), that exhibit a wide variety of interesting and potentially useful physical phenomena. It is already known that the magnetocaloric effect in the Heusler alloys is fundamentally connected to other interesting phenomena such as shape-memory properties. And the large magnetic entropy change in Ni2Mn0.75Cu0.25Ga has been attributed to the coupling of the first-order, martensitic transition with the second-order ferromagnetic paramagnetic (FM-PM) transition. Our research to this point has focused on understanding the fundamental physics at the origin of these complex, compound phase transitions, and the novel properties that emerge. We synthesize the materials using a variety of techniques, and explore their material properties through structural, magnetic, transport, and thermo-magnetic measurements.