Phase Transition, Magnetocaloric Effect, and Critical Behavior of Room Temperature Magnetic Refrigerant Material Mn5Ge2.7Zn0.3

• Published in: Shànghăi jiāotōng dàxué xuébào Vol. 59; no. 1; pp. 131 - 138
• Main Author: XU Tongjie, LIU Zhenhua, JIN Huaiyu, LIU Jie, JIANG Xiuli, LI Zhe, LIU Yongsheng
• Format: Journal Article
• Language: Chinese
• Published: Editorial Office of Journal of Shanghai Jiao Tong University 01.01.2025
• Subjects: critical behavior; interaction; magnetocaloric effect; mn5ge3 based alloys; second-order phase transition
• ISSN: 1006-2467
• DOI: 10.16183/j.cnki.jsjtu.2023.112

Mn5Ge2.7Zn0.3 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 M2-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