中文摘要：

通过电弧熔炼的方法制备了Mn20Ni42-xFeSn9合金（x=0，2，4）。采用X射线衍射、综合物性测试系统、振动样品磁强计对合金的晶体结构、相变、磁热效应和交换偏置效应进行了研究。结果表明，随着Fe含量的增加，马氏体转变温度逐渐降低，马氏体居里温度逐渐增加。Fe的加入使材料马氏体相变附近的磁化强度的变化增加，从而使其具有较大的磁热效应。另外，Fe的加入使材料的交换偏置场逐渐降低，这可以用Fe掺杂导致的铁磁交换作用的增强来解释。

英文摘要：

Mn50 Ni41-x FexSn9 （x = 0,2,4）alloys were prepared by arc melting method. Their crystal structure, phase transitions, magnetocaloric effect, and exchange bias were investigated by X-ray diffraction, physical property measurement system, and vibrating sample magnetometer. The results show that with the increase of Fe content, the martensitic transformation temperature decreases gradually, while Curie temperature of the martensitic phase increases.The addition of Fe leads to the increase in the magnetization change across the martensitic transformation,which gives rise to relatively large magnetocaloric effect. Furthermore, the exchange bias field decreases with the increasing of Fe concentration,which is ascribed to the fact that Fe addition can enhance the ferromagnetic interaction in Mn50 Ni41-x Fex an9 alloys.