Zhu Yinghao, Xia Junchao, Wu Si, Sun Kaitong, Yang Yuewen, Zhao Yanling, Kan Hei Wun, Zhang Yang, Wang Ling, Wang Hui, Fang Jinghong, Wang Chaoyue, Wu Tong, Shi Yun, Yu Jianding, Zhang Ruiqin, Li Hai-Feng
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macao SAR 999078, China.
Department of Physics, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China.
iScience. 2022 Mar 18;25(4):104111. doi: 10.1016/j.isci.2022.104111. eCollection 2022 Apr 15.
We report a combined experimental and theoretical study on intriguing magnetic properties of quasiferroelectric orthochromates. Large single crystals of the family of RECrO (RE = Y, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) compounds were successfully grown. Neutron Laue study indicates a good quality of the obtained single crystals. Applied magnetic field and temperature dependent magnetization measurements reveal their intrinsic magnetic properties, especially the antiferromagnetic (AFM) transition temperatures. Density functional theory studies of the electronic structures were carried out using the Perdew-Burke-Ernzerhof functional plus Hubbard method. Crystallographic information and magnetism were theoretically optimized systematically. When RE cations vary from Y and Eu to Lu ions, the calculated - orbital hybridization degree and Néel temperature behave similarly to the experimentally determined AFM transition temperature with variation in cationic radius. We found that the - hybridization is anisotropic, causing a magnetic anisotropy of Cr sublattices. This was evaluated with the nearest-neighbor - model. Our research provides a picture of the electronic structures during the - hybridization process while changing RE ions and sheds light on the nature of the weak ferromagnetism coexisting with predominated antiferromagnetism. The available large RECrO single crystals build a platform for further studies of orthochromates.
我们报告了一项关于准铁电正铬酸盐有趣磁性质的实验与理论相结合的研究。成功生长出了RECrO（RE = Y、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb和Lu）化合物家族的大尺寸单晶。中子劳厄研究表明所获得的单晶质量良好。施加磁场和温度依赖的磁化强度测量揭示了它们的本征磁性质，特别是反铁磁（AFM）转变温度。使用Perdew - Burke - Ernzerhof泛函加哈伯德方法对电子结构进行了密度泛函理论研究。对晶体学信息和磁性进行了系统的理论优化。当RE阳离子从Y和Eu变化到Lu离子时，计算得到的 - 轨道杂化程度和奈尔温度与实验测定的AFM转变温度随阳离子半径变化的情况类似。我们发现 - 杂化是各向异性的，导致Cr亚晶格出现磁各向异性。这是用最近邻 - 模型进行评估的。我们的研究提供了在改变RE离子时 - 杂化过程中的电子结构图景，并揭示了与主导反铁磁性共存的弱铁磁性的本质。现有的大尺寸RECrO单晶为正铬酸盐的进一步研究搭建了一个平台。
