Tereshina I S, Kostyuchenko N V, Tereshina-Chitrova E A, Skourski Y, Doerr M, Pelevin I A, Zvezdin A K, Paukov M, Havela L, Drulis H
Faculty of Physics, Lomonosov Moscow State University, 119991, Moscow, Russia.
Moscow Institute of Physics and Technology, Dolgoprudny, Moscow region, 9 Institutsky Per., Dolgoprudny, 141700, Russia.
Sci Rep. 2018 Feb 26;8(1):3595. doi: 10.1038/s41598-018-21756-5.
Rare-earth (R)-iron alloys are a backbone of permanent magnets. Recent increase in price of rare earths has pushed the industry to seek ways to reduce the R-content in the hard magnetic materials. For this reason strong magnets with the ThMn type of structure came into focus. Functional properties of R(Fe,T) (T-element stabilizes the structure) compounds or their interstitially modified derivatives, R(Fe,T)-X (X is an atom of hydrogen or nitrogen) are determined by the crystal-electric-field (CEF) and exchange interaction (EI) parameters. We have calculated the parameters using high-field magnetization data. We choose the ferrimagnetic Tm-containing compounds, which are most sensitive to magnetic field and demonstrate that TmFeTi-H reaches the ferromagnetic state in the magnetic field of 52 T. Knowledge of exact CEF and EI parameters and their variation in the compounds modified by the interstitial atoms is a cornerstone of the quest for hard magnetic materials with low rare-earth content.
稀土（R）-铁合金是永磁体的核心材料。近期稀土价格的上涨促使该行业寻求降低硬磁材料中稀土含量的方法。因此，具有ThMn型结构的强磁体成为了研究重点。R(Fe,T)（T元素使结构稳定）化合物或其间隙改性衍生物R(Fe,T)-X（X为氢或氮原子）的功能特性由晶体电场（CEF）和交换相互作用（EI）参数决定。我们利用高场磁化数据计算了这些参数。我们选择了对磁场最敏感的含Tm亚铁磁化合物，并证明TmFeTi-H在52 T的磁场中达到铁磁状态。了解精确的CEF和EI参数及其在间隙原子改性化合物中的变化，是寻求低稀土含量硬磁材料的基石。
