室温磁致冷材料Mn_(5)Ge_(2.7)Zn_(0.3)的相变、磁热效应和临界行为  

Phase Transition,Magnetocaloric Effect,and Critical Behavior of Room Temperature Magnetic Refrigerant Material Mn_(5)Ge_(2.7)Zn_(0.3)

作　　者：许童杰 刘振华 金怀宇 刘结 蒋秀丽 李哲 刘永生 XU Tongjie;LIU Zhenhua;JIN Huaiyu;LIU Jie;JIANG Xiuli;LI Zhe;LIU Yongsheng(College of Mathematics and Physics,Shanghai University of Electric Power,Shanghai 200090,China;Center for Magnetic Materials and Devices,Qujing Normal University,Qujing 655011,Yunnan,China)

机构地区：[1]上海电力大学数理学院,上海200090 [2]曲靖师范学院磁性材料及器件研究中心,云南曲靖655011

出　　处：《上海交通大学学报》2025年第1期131-138,共8页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金项目(51971128);国家自然科学基金项目(52171185);上海市优秀学术/技术带头人项目(20XD1401800)。

摘　　要：通过电弧熔炼法成功制备了Mn_(5)Ge_(2.7)Zn_(0.3)合金,并对其相变、磁热效应和临界行为等进行研究.利用热磁曲线确定了样品的居里温度为297.2 K,等温磁化曲线发现样品没有热滞,通过M2-H/M曲线和Banerjee准则证实样品经历了二级相变,进一步根据Maxwell方程计算样品的等温熵变,场-熵的幂律关系和归一化曲线也验证了二级相变.利用modified Arrott plot(MAP)法、Kouvel-Fisher(KF)法和等温磁化(CI)法求解临界指数,并用Widom标度定律和标度方程验证了临界指数的准确性.最后利用Arrott-Noaks方程对样品的临界行为进一步分析,归一化斜率和磁相互作用距离的分析证实了样品内部磁相互作用的复杂性.Mn_(5)Ge_(2.7)Zn_(0.3)alloy was successfully prepared by using the arc-melting method,and its phase transition,magnetocaloric effect,and critical behavior were studied.The thermomagnetic curve determined that the Curie temperature of the sample was 297.2 K,the isothermal magnetization curve found that the sample had no thermal hysteresis.The sample underwent a second-order phase transition through the M 2-H/M plot and Banerjee’s criterion,and the isothermal entropy change of the sample was further calculated according to Maxwell’s equation,and the power-law relationship of field-entropy and the normalization curve also verified the fact of the second-order phase transition.The critical index was solved by the modified Arrott plot(MAP)method,the Kouvel-Fisher(KF)method and the critical isothermal(CI)method,and the accuracy of the critical index was verified by Widom scaling ansatz and scaling laws.Finally,the Arrott-Noaks equation was used to further analyze the critical behavior of the sample,and the normalization slope and magnetic interaction distance were analyzed to confirm the complexity of the magnetic interaction inside the sample.

关 键 词：Mn_(5)Ge_(3)基合金 二级相变 磁热效应 临界行为 相互作用 

分 类 号：TB64[一般工业技术—制冷工程] O482.6[理学—固体物理]