Effect of proportion change of aluminum and silicon on magnetic entropy change and magnetic properties in La_0.8Ce_0.2Fe_11.5Al_1.5-xSi_x compounds

傅斌¹，韩洁²，王超伦³

1. School of Materials Science and Engineering, Tianjin University of Technology2. College of Science, Tianjin University of Technology3. Department of Electrical Engineering, East China Normal University

摘 要：The microstructure, magnetic entropy changes, hysteresis and magnetic properties of La_0.8Ce_0.2Fe_11.5Al_1.5–xSi_x（x=0.4, 0.5, 0.6, 0.7） compounds were studied by X-ray diffraction（XRD） and a superconducting quantum interference device magnetometer（SQUID）. The results showed that all the compounds presented cubic Na Zn13-type structure. Their Curie temperatures changed complicatedly with decreasing Al content due to changes of antiferromagnetic and ferromagnetic interaction. Under a field change from 0 to 2 T, the maximum magnetic entropy change for La_0.8Ce_0.2Fe_11.5Al_1.1Si_0.4, La_0.8Ce_0.2Fe_11.5Al_1.0Si_0.5, La_0.8Ce_0.2Fe_11.5Al_0.9Si_0.6 and La_0.8Ce_0.2Fe_11.5Al_0.8Si_0.7 were found to be –9.6, –4.8, –5.8 and –11.7 J/（kg·K）, respectively. Moreover, their hysteresis losses were 1.13 J/（kg·K） or less. The large magnetic entropy changed and small hysteresis losses made them potential candidates for practical magnetic refrigeration application.

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