Xu Kun, Gu Youdi, Song Cheng, Zhong Xiaoyan, Zhu Jing
National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
Nanoscale. 2021 Mar 28;13(12):6066-6075. doi: 10.1039/d0nr07697j. Epub 2021 Feb 22.
Novel phenomena and functionalities at interfaces of oxide heterostructures are currently of great interest in a wide range of applications. At such interfaces, charge, spin, orbital and lattice ordering coexist and correlate closely, contributing to rich functional responses. By using atomically resolved imaging and spectroscopy techniques, we investigated magnetic behaviors and structural modulation at the SrFeO/SrTiO interface. Fe/Ti element intermixing and oxygen vacancies occurred across a few unit cells at the interface. Furthermore, antiferromagnetic spin ordering of Fe with different valence states in the interface of SrFeO/SrTiO induced uncompensated magnetic moments. Compared to the SrFeO/LaSrAlTaO heterojunction, the variations of charge and lattice order parameters at the SrFeO/SrTiO interfaces were also determined by advanced electron microscopy, which provided a good understanding of the physical origin of disparate macroscopic magnetic properties, further investigated by magnetometer measurements and X-ray magnetic circular dichroism (XMCD) spectra. These studies provide comprehensive insight into the interfacial modulation of ferrite oxide, which may be useful for designing future devices in oxide electronics.
目前，氧化物异质结构界面处的新奇现象和功能在广泛的应用中备受关注。在这样的界面处，电荷、自旋、轨道和晶格有序共存且紧密相关，从而产生丰富的功能响应。通过使用原子分辨成像和光谱技术，我们研究了SrFeO/SrTiO界面处的磁行为和结构调制。Fe/Ti元素混合和氧空位在界面处跨越几个晶胞出现。此外，SrFeO/SrTiO界面中不同价态Fe的反铁磁自旋有序诱导了未补偿的磁矩。与SrFeO/LaSrAlTaO异质结相比，SrFeO/SrTiO界面处电荷和晶格有序参数的变化也通过先进的电子显微镜确定，这有助于很好地理解不同宏观磁性能的物理起源，通过磁力计测量和X射线磁圆二色性（XMCD）光谱进一步研究。这些研究为铁氧体氧化物的界面调制提供了全面的见解，这可能有助于设计未来的氧化物电子器件。
