Symmetry‐Mismatch‐Induced Ferromagnetism in the Interfacial Layers of CaRuO 3 /SrTiO 3 Superlattices
作者：Wenxiao Shi, Jine Zhang, Xiaobing Chen, Qinghua Zhang, Xiaozhi Zhan, Zhe Li, Jie Zheng, Mengqin Wang, Furong Han, Hui Zhang, Lin Gu, Tao Zhu, Bang‐Gui Liu, Yunzhong Chen, Yunzhong Chen, Fengxia Hu, Baogen Shen, Yuansha Chen, Yuansha Chen, Jirong Sun · 发表于：Advanced Functional Materials · 年份：2023 · DOI：10.1002/adfm.202300338 · 被引用次数：19 · 研究领域：Advanced Condensed Matter Physics、Magnetic and transport properties of perovskites and related materials、Multiferroics and related materials
Abstract By modifying the entangled multi‐degrees of freedom of transition‐metal oxides, interlayer coupling usually produces interfacial phases with unusual functionalities. Herein, a symmetry‐mismatch‐driven interfacial phase transition from paramagnetic to ferromagnetic state is reported. By constructing superlattices using CaRuO 3 and SrTiO 3 , two oxides with different oxygen octahedron networks, the tilting/rotation of oxygen octahedra near interface is tuned dramatically, causing an angle increase from ≈150° to ≈165° for the RuORu bond. This in turn drives the interfacial layer of CaRuO 3 , ≈3 unit cells in thickness, from paramagnetic into ferromagnetic state. The ferromagnetic order is robust, showing the highest Curie temperature of ≈120 K and the largest saturation magnetization of ≈0.7 µ B per formula unit. Density functional theory calculations show that the reduced tilting/rotation of RuO 6 octahedra favors an itinerant ferromagnetic ground state. This work demonstrates an effective phase tuning by coupled octahedral rotations, offering a new approach to explore emergent materials with desired functionalities.