Li Zhe, Chen Xiaobing, Chen Yuansha, Zhang Qinghua, Zhang Hui, Zhang Jine, Shi Wenxiao, He Bin, Zhang Jinxing, Song Jinghua, Han Furong, Liu Banggui, Gu Lin, Hu Fengxia, Chen Yunzhong, Shen Baogen, Sun Jirong
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
Mater Horiz. 2021 Nov 29;8(12):3468-3476. doi: 10.1039/d1mh01385h.
Heterostructures composed of dissimilar oxides with different properties offer opportunities to develop emergent devices with desired functionalities. A key feature of oxide heterostructures is interface electronics and orbital reconstructions. Here, we combined infinite-layered SrCuO and perovskite SrRuO into heterostructures. A rare high spin state as large as 3.0 f.u and an increase in Curie temperature by 12 K are achieved in an ultrathin SrRuO film capped by a SrCuO layer. Atomic-scale lattice imaging shows the uniform CuO-plane-to-RuO-pyramid connection at the interface, where the regularly arranged RuO pyramids were elongated along the out-of-plane direction. As revealed by theoretical calculations and spectral analysis, these features finally result in an abnormally high spin state of the interfacial Ru ions with highly polarized e orbitals. The present work demonstrates that oxygen coordination engineering at the infinite-layer/perovskite oxide interface is a promising approach towards advanced oxide electronics.
由具有不同性质的不同氧化物组成的异质结构为开发具有所需功能的新兴器件提供了机会。氧化物异质结构的一个关键特征是界面电子学和轨道重构。在此，我们将无限层SrCuO和钙钛矿SrRuO组合成异质结构。在由SrCuO层覆盖的超薄SrRuO薄膜中实现了高达3.0 f.u的罕见高自旋态以及居里温度升高12 K。原子尺度晶格成像显示界面处CuO平面与RuO金字塔之间的均匀连接，其中规则排列的RuO金字塔沿面外方向拉长。正如理论计算和光谱分析所揭示的，这些特征最终导致界面Ru离子具有异常高的自旋态，其e轨道高度极化。目前的工作表明，无限层/钙钛矿氧化物界面处的氧配位工程是实现先进氧化物电子学的一种有前途的方法。
