【作者】 张泽玉； 段静芳； 王东； 张虎； 叶荣昌； 常永勤； 龙毅； 万发荣；

【Author】 Zhang Zeyu, Duan Jingfang, Wang Dong, Zhang Hu, Ye Rongchang, Chang Yongqin, Long Yi, Wan Farong (School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 , China )

【机构】 北京科技大学材料科学与工程学院；

【摘要】 通过向NiMnGa合金中添加稀上元素Gd,制备了Ni56Mn18.8Ga24.5Gdo.7合金。该合金室温下保持马氏体结构,随温度升高发生了由铁磁性马氏体向顺磁性奥氏体的转变。稀土元素Gd的添加,使得合金晶粒得到细化,并且Gd元素在晶界处富集。交流磁化率结果表明, Ni56Mn18.8Ga24.5Gd0.7合金的奥氏体结构转变与磁性转变同时发生。Ni56Mn18.8Ga24.5Gd0.7合金在1．9 T的磁场下获得了13．4 J·kg-1·K-1的高磁熵变结果。更多还原

【Abstract】 With the addition of gadolinium, the Ni56 Mn18.8Ga24.5Gd0.7 alloy keeps martensite structural at room temperature and transfers from ferromagnetic mantensite phase to paramagnetic austenitic phase with the rising temperature. The max magnetic entropy change is 13.4 J·2kg-1·K-1 under 1.9 T field at 338 K. The giant magnetocaloric effect found in Ni56Mn18.8 Ga24.5Gd0.7 alloy is due to concurrently occurring first order structural and magnetic phase transitions, whereby the transition spreads over a narrow temperature range of about 5 K.更多还原