中文摘要：

采用电弧熔炼的方法制备了Ni43Mn46Sn11-xGax （x=0,1,2） 合金铸锭. 用X射线衍射表征样品的晶体结构,用振动样品磁强计和综合物性测试系统测量样品的相变和磁热效应. 结果表明,所有合金在室温下均为奥氏体立方结构,表明马氏体转变温度低于室温. Ga代替Sn导致马氏体转变温度升高,这是由于Ga的原子半径小于Sn,导致晶格变小. 所有样品在马氏体转变伴随着较大的磁化强度的突变,从而表现出较大的低场磁熵变. Ni43Mn46Sn11-xGax （x=0,1,2） 以其较大的低场磁热效应、可调的工作温区在磁制冷领域有着潜在的应用.

英文摘要：

Ni43Mn46Sn11-xGax（x=0,1,2） alloy ingots were prepared by arc melting method. The crystal structure of the samples was characterized by X-ray diffraction. The phase transformation and magnetocaloric effects of the samples were measured with a Vibrating Sample Magnetometer and a Physical Property Measurement System. The results show that all samples have austenitic cubic structure at room temperature, indicating that the martensitic transition temperature is lower than room temperature. The martensitic transformation temperatures increase with the substitution of Sn by Ga,which is due to the fact that the atomic radius of Ga is less than Sn, resulting in a decrease in lattice constant. All samples undergo a large abrupt change of magnetization in the vicinity of martensitic transformation, which implies a large low-field magnetic entropy change. Ni43Mn46Sn11-xGax（x=0,1,2） alloys have a potential application in the field of magnetic refrigeration, due to its large low-field magnetocaloric effect and adjustable working temperature.