摘要
稀土Fe基3:29和1:12型磁性合金化合物显示硬磁性特征,具有发展成为新型永磁材料的可能性.研究其磁性机理有助于理解其磁性的本质.本文发展了传统的磁价模型,并将其适用性由强磁合金拓展到亚铁磁性的弱磁性合金.利用发展的磁价模型系统研究RFe12xMx,R3Fe29xMx和R2Fe17xMx(R=稀土元素,M=第三掺杂金属元素)稀土合金化合物及其渗碳和吸氮化合物的磁性.理论与实验相符.研究表明:稀土Fe基3:29和1:12型合金化合物的磁性与稀土磁矩相关.合金的弱磁性源于合金内部存在的亚铁磁性.渗碳或吸氮处理,导致合金内部亚铁性-铁磁性转变.导带中的sp电子对于磁性的贡献与重稀土的极化、碳和氮原子的俘获密切相关.发展的磁价模型甚至可以根据稀土化合物的结构式对其磁性进行预测.
The rare earth-iron based 3：29 and 1：12 type intermetallic compounds have the potential application as novel permanent magnetic materials due to their hard magnetic properties at room temperature. The study on the magnetism of these intermetallic compounds is beneficial for the research and development of their applications as novel rare earth permanent magnetic materials. In this study, the traditional magnetic valence model has been developed for extending its application from the strong magnetic alloys and intermetallic compounds to the weak magnetic systems with ferrimagnetic order. The developed magnetic valence model has been used to investigate the magnetisms of RFe12 x M x , R3Fe29 x M x and R2Fe17xM x （R=rare earth; M= the doped metals such as Ti, Mo, V, etc） and their carbonates and nitrides. The theoretical calculations agree with the experiments well. The study shows that the magnetic moments of these kinds of rare earth iron based intermetallic compounds are related to the magnetisms of the rare earths in these intermetallic compounds. The weak magnetism in these intermetallics originates from the existence of some ferrimagnetic order pairs in the unit cell. The nitrogenation and carbonation process might induce the ferrimagnetic order pairs transiting to the ferromagnetic order pairs, and increase their moments. The contributions to the magnetic moments of the electrons in conducting band are related to the polarization of heavy rare earth and the capture abilities of carbon and nitrogen atoms to electrons. The developed magnetic valence model can predict the magnetic moments as long as the structural formula is known.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2013年第1期31-38,共8页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金资助项目(批准号:51141006
11274110)
关键词
磁价模型
亚铁磁性
稀土合金化合物
magnetic valence model
ferromagnetic order
rare earth intermetallics
