短周期氧化物超晶格中的电荷转移及其应变调控

项目名称： 短周期氧化物超晶格中的电荷转移及其应变调控

项目编号： No.11504358

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 黄浩亮

作者单位： 中国科学技术大学

项目金额： 24万元

中文摘要： 氧化物界面上的电荷转移是实现全新电子态或磁性基态的重要途径，理解应变与电荷转移之间的关系是界面应用的重要环节。因此，本项目拟通过考虑不同应变状态对基于SrCoOx的短周期超晶格外延薄膜电输运、磁学性能的影响，研究超晶格中应变-物性之间的关系；采用原位X射线技术，通过测量超晶格中Co离子的多重价态变化，研究电荷在Co与其它过渡金属离子（如Co-Co、Co-Mn、Co-Fe等）之间的转移；利用材料物性对应变状态的敏感，根据压电衬底晶格的电场可调性，实现电场调控超晶格薄膜中的电荷转移，研究电荷转移的动态过程。该研究对揭示界面上晶格-电荷-自旋之间的相互耦合关系有重要意义，有助于探究强关联电子体系中的多参量耦合，有利于开发基于电场调控的低功耗多功能器件。

中文关键词： 电荷转移；应变调控；超晶格；晶格畸变；同步辐射

英文摘要： Charge transfer at oxide interfaces has been one of the most popular pathways toward realizing new electronic and magnetic states in oxide heterostructures. The relationship between strain and charge transfer is an important part of interface applications. This proposal will research on the strain effect on the electrical transport and magnetic properties in short period superlattice epitaxial thin films, which contain SrCoOx, to study the relation between strain and physical properties. And then the charge transfer between Co and other transition metal ions (such as Co-Co, Co-Mn or Co-Fe) will be illustrated through measurement of multiple valence of Co ions by in situ X-ray technology. Moreover, the dynamic process of charge transfer which is modified by electrical field will be analyzed according to the controllable lattice of piezoelectric substrate. This work is of significant importance for reveals the interactions between lattice, charge and spin. It will help us to comprehend the coupling mechanism in the complex multi-parameters process, and design low-power multifunctional device which based on the electrical field control.

英文关键词： charge transfer;strain engineering;superlattice;lattice distortion;synchrotron radiation