摘要
NaZn_(13)型LaFe_(13-x)Si_(x)合金是一种具有应用前景的室温制冷材料.文中使用工业纯的La-Ce-Pr-Nd混合稀土替代La元素,制备了名义成分为(La-Ce-Pr-Nd)_(1)Fe_(13-x)Si_(x)系列合金,研究了该系列合金的物相组成和磁热性能.XRD精修结果表明,合金中除了立方结构的主相外,还有其他3种不同结构的杂相,与扫描电镜背散射图谱分析结果吻合.合金的热磁曲线表明,随着温度的升高,所有合金均发生从铁磁态向顺磁态转变的二级相变.当合金中的摩尔比例在0~2 T外磁场的作用下,合金的最大等温磁熵变从4.5 J/kgK下降至2.6 J/kgK.研究结果对探索混合稀土在磁热材料中的应用提供有益参考.
NaZn_(13)-type LaFe_(13-x)Si_(x)alloys are regarded as potential magnetocaloric materials for magnetic refrigeration near room temperature.Herein,La-Ce-Pr-Nd industrial mischmetal instead of pure La was used as raw material to prepare a series of alloys with nominal composition of(La-Ce-Pr-Nd)_(1)Fe_(13-x)Si_(x).Analyses of X-ray diffraction patterns indicated that except for the main phase of cubic 1∶13 structure,three other secondary phases coexisted in the alloys,which was also confirmed by backscattered electron microscope measurement.Second order transition from ferromagnetic to paramagnetic state was observed in the thermal magnetization curve for each alloy.Under a field change of 0-2 T,the maximum isothermal entropy change of the 1∶13 phase decreased monotonously from 4.5 J/kgK to 2.6 J/kgK when increasing the mole ratio of Si from 2.0 to 2.5.The present study provides valuable reference for developing magnetocaloric materials using industrial mischmetal.
作者
王高峰
顾庆典
刘鑫
任伟
WANG Gaofeng;GU Qingdian;LIU Xin;REN Wei(Science School,Inner Mongolia University of Science and Technology,Baotou 014010,China;Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014010,China)
出处
《内蒙古科技大学学报》
CAS
2023年第1期10-14,共5页
Journal of Inner Mongolia University of Science and Technology
基金
国家自然科学基金资助项目(11564030)
内蒙古自治区自然科学基金资助项目(2021LHMS01005).
关键词
物相组成
磁热效应
合金
混合稀土
phase constituent
magnetocaloric effect
alloy
mischmetal
