【摘要】 采用电弧熔炼方法制备了Ni₄₃Mn₄₆Sn₉Ga₂合金,并对其磁相变、磁熵变和相变临界行为进行了研究.随温度升高,材料依次经历自旋玻璃-铁磁马氏体-顺磁马氏体-铁磁奥氏体-顺磁奥氏体一系列相变.在奥氏体居里温度268 K时,材料在5 T磁场下的磁熵变达到-3.33 J/（kg·K）.Ni₄₃Mn₄₆Sn₉Ga₂合金的临界指数为β=0.536,γ=1.381,δ=3.577,居里温度以下符合平均场理论,居里温度以上符合三维Heisenberg模型.更多还原

【Abstract】 Ni₄₃Mn₄₆Sn₉Ga₂ alloy is synthesized by arc melting method, and its magnetic phase transition, magnetic entropy change, and critical behavior were studied. With the temperature increasing, Ni₄₃Mn₄₆Sn₉Ga₂ undergoes spin glass-ferromagnetic, martensite-paramagnetic, martensite-ferromagnetic and austenite-paramagnetic austenite transitions. The magentic entropy change is-3.33 J/（kg·K） for the magnetic field of 5 T at 268 K. The values of critical exponents are β=0.536, γ=1.381, δ=3.577, consistent with the mean field theory below TCA, and 3D Heisenberg model above TC^A.更多还原