Lin Shan, Zhang Qinghua, Sang Xiahan, Zhao Jiali, Cheng Sheng, Huon Amanda, Jin Qiao, Chen Shuang, Chen Shengru, Cui Wenjun, Guo Haizhong, He Meng, Ge Chen, Wang Can, Wang Jiaou, Fitzsimmons Michael R, Gu Lin, Zhu Tao, Jin Kuijuan, Guo Er-Jia
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Nano Lett. 2021 Apr 14;21(7):3146-3154. doi: 10.1021/acs.nanolett.1c00352. Epub 2021 Mar 22.
Manipulation of octahedral distortion at atomic scale is an effective means to tune the ground states of functional oxides. Previous work demonstrates that strain and film thickness are variable parameters to modify the octahedral parameters. However, selective control of bonding geometry by structural propagation from adjacent layers is rarely studied. Here we propose a new route to tune the ferromagnetism in SrRuO (SRO) ultrathin layers by oxygen coordination of adjacent SrCuO (SCO) layers. The infinite-layered CuO exhibits a structural transformation from "planar-type" to "chain-type" with reduced film thickness. Two orientations dramatically modify the polyhedral connectivity at the interface, thus altering the octahedral distortion of SRO. The local structural variation changes the spin state of Ru and orbital hybridization strength, leading to a significant change in the magnetoresistance and anomalous Hall resistivity. These findings could launch investigations into adaptive control of functionalities in quantum oxide heterostructures using oxygen coordination.
在原子尺度上操纵八面体畸变是调节功能氧化物基态的有效手段。先前的工作表明，应变和薄膜厚度是改变八面体参数的可变参数。然而，通过相邻层的结构传播对键合几何结构进行选择性控制的研究很少。在这里，我们提出了一种通过相邻SrCuO（SCO）层的氧配位来调节SrRuO（SRO）超薄层中铁磁性的新途径。无限层CuO随着薄膜厚度的减小呈现出从“平面型”到“链型”的结构转变。两种取向显著改变了界面处的多面体连通性，从而改变了SRO的八面体畸变。局部结构变化改变了Ru的自旋态和轨道杂化强度，导致磁电阻和反常霍尔电阻率发生显著变化。这些发现可能会引发关于利用氧配位对量子氧化物异质结构中的功能进行自适应控制的研究。
