Magnetocaloric effect of La_0.7?xPr_xCa_0.3MnO₃ perovskites

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• 作者：Masahiro Suemitsu ; Takashi Nakagawa ; ^{nakagawa@mit.eng.osaka-u.ac.jp} ; Yusuke Hirayama ; Satoshi Seino ; Takao A. Yamamoto
• 关键词：Magnetic entropy change ; Adiabatic temperature change ; Relative cooling power ; First order transition ; Second order transition ; Perovskite
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：25 February, 2013
• 年：2013
• 卷：551
• 期：Complete
• 页码：195-199
• 全文大小：613 K

文摘

The magnetic properties and the magnetocaloric effect (MCE) of La_0.7?xPr_xCa_0.3MnO₃ perovskite materials (0 ? x ? 0.69) were investigated. Magnetic entropy changes (¦¤S_M) were calculated both from magnetization data using Maxwell¡¯s relation and specific heat data. With increasing x, the Curie temperature T_C decreases from 240 to 119 K. The maximum value of ¦¤S_M, the adiabatic temperature change (¦¤T_ad), and the relative cooling power (RCP) induced by demagnetization from 1 to 0 T were 6.8 J/kg K, 2.5 K, and 54 J/kg at 225 K, for x = 0.1. These parameters were about 200 % , 80 % , and 65 % of the comparable Gd parameters, indicating that these materials are promising candidates as magnetic refrigerants in the sub-room temperature range (200-250 K).