摘要
采用固相反应的方法制备Mn_3GaC化合物,并对其相变和磁性进行了研究.结果表明,Mn_3GaC经历了一个一级相变和两个二级相变.通过Maxell关系计算一级相变附近的磁熵变,发现其结果对磁化曲线的测量过程非常敏感,采用非连续升温测量方式可以避免误差的产生.对比一级相变和二级相变附近的磁热效应,一级相变磁熵值和磁滞较大,有效制冷能力较小;而二级相变附近的磁熵值较小,制冷能力较大.
Mn3GaC compound was prepared by solid state reaction, and its magnetic properties, phase transi-tions, and magnetocaloric effect were investigated. Mn3GaC undergoes a first-order transition and two second-or-der transition. It was found that the magnetic entropy change calculated by Maxell relation is dependent on the process of isothermal magnetization. Compared with the magnetocaloric effect near second-order transition, first-order transition is of large magnetic entropy change, large magnetic hysteresis, and small refrigerant capaci-ty.
出处
《常熟理工学院学报》
2013年第2期10-13,60,共5页
Journal of Changshu Institute of Technology
基金
国家自然科学基金项目"Ni-Mn基铁磁形状记忆合金的磁热效应研究"(51001019)
江苏省大学生实践创新训练计划项目"新型Mn基磁制冷材料的研究"(JX110152012)
关键词
磁热效应
磁熵变
一级相变
二级相变
magnetocaloric effect
magnetic entropy change
first-order transition
second-order transition
