(1. 内江师范学院,物理与电子信息工程学院,内江 641112;
2. The Ames Laboratory, Department of Energy of the Unite States, Iowa State University, Ames, Iowa 50011-3020, USA)
摘 要: 本文以X射线粉末衍射谱、等温磁化曲线和等磁场变温曲线为基础,研究了Er-Fe-In三元系773 K等温截面相图与Er12Fe2In3化合物的磁性。结果表明:该三元系中只有一个三元化合物Er12Fe2In3存在,且二元化合物与三元化合物均未观察到固溶现象。化合物的磁性研究表明,低场下Er12Fe2In3合金分别在10 K出现了一个正常反铁磁-顺磁相变以及在36 K出现一个类似反铁磁-顺磁的磁相变。磁化过程中存在磁场诱导反铁磁-铁磁相变,在2 T以上磁场中该合金只在居里温度约12 K时存在铁磁-顺磁相变。在0~5 T磁场范围内,合金的最大等温磁熵变(-ΔSMax)为9.9 J/(kg·K),在等温磁熵变最大值半高宽ΔTcycl=38.0 K(5.7~43.7 K)范围内,其相对制冷能力为278.1 J/kg。
关键字: Er-Fe-In相图;RE3×4(T2)4-xXx相;变磁相变;磁热效应
(1. College of Physics and Electronic Information Engineering, Neijiang Normal University, Neijiang 641100, China;
2. The Ames Laboratory, Department of Energy of the Unite States, Iowa State University, Ames, Iowa 50011-2416, USA)
Abstract:The isothermal section of the Er-Fe-In system at 773 K was constructed by X-ray powder diffraction (XRD) in this paper. One known ternary compound, Er12Fe2In3 has been confirmed. At the same time, Solid solutions were not detected in Er-Fe-In system at 773 K. The magnetic transition and magnetocaloric effect of Er12Fe2In3 alloy were investigated by magnetic susceptibility and isothermal magnetization measurements. One normal antiferromagnetic-paramagnetic transition and another abnormal one occur at 10 K and 36 K in ground state, respectively. Due to the field-induced antiferromagnetic-ferromagnetic states at/below the Néel, there is only a second order ferromagnetic- paramagnetic with TC=12 K in a high field. The maximum entropy change (-ΔSMax) values are -9.9 J/(kg?K) near TC. In the magnetic field range of 0-5 T, the reversible RCP corresponding to negative entropy change is 278.1 J/kg in an wide operating temperature region ΔTcycl=38 K, from 5.7 K to 43.7 K.
Key words: Er-Fe-In ternary phase diagram; RE3(x+y)(T2)xXy phase; metamagnetic transition; magnetothermal properties