纳米复合尖晶石铁氧体薄膜的电致阻变及磁性调控机理研究

Resistive memory based on resistive switching effect is an important directon of next-generation nonvolatile memory. Understanding the physical mechanism of the resistive switching effect and developing high performance resistive switching materials are the key fundamental problems to be solved. Our recent research indicated that Au,Ag nanocomposited spinel ferrite thin films had excellent resistive switching effect. Doping Au and Ag nanoparticles leads to a change in distribution and migration process of defects under electric field in the thin films as well as magnetic exchange coupling, which allows regulation of resistive switching and magnetic properties. Based on this research results, we put forward to further studying the physical meachanism of the regulation of resistive switching and magnetic properties of the nanocomposite ferrite thin films. By studying the compositions, microstructure, surface and interface structure of the composite thin films, and taking into consideration of special structure of spinel ferrite materials, through defect formation and control, and optimized interfacial structure design, the correlation between transport property of carriers, magnetic property, and resistive switching performance of the nanocomposite thin films under temperature, electric field and magnetic field and electromagnetic coupling phenomena will be studied, and the physical mechanisms of tuning resistive switching effect and magnetic property and electromagnetic coupling effect will be well understood. This project will provide a useful reference for design and preparation of new nanocomposite resistive switching thin films and further nonvolatile memory applications.

基于电致阻变效应的电阻式存储器是下一代非挥发存储器发展的重要方向，认识电致阻变效应的物理机制并开发性能优异的电致阻变材料是需要解决的关键基础问题。我们最近的研究显示，金银纳米复合尖晶石铁氧体薄膜具有优异的电致阻变特性，由于金银纳米颗粒的掺入改变了薄膜中缺陷的分布及电场作用下的迁移过程，同时也引起磁交换耦合的变化，因此可以实现电致阻变特性和磁性的调控。以此为基础，我们提出进一步开展纳米复合铁氧体薄膜的电致阻变特性及磁性调控的物理机制研究。通过研究纳米复合薄膜的组成和微结构、表面界面结构，并考虑到尖晶石铁氧体结构的特殊性，通过缺陷形成与控制以及界面结构设计，探讨温度、电场和磁场作用下载流子的输运特性、磁性与电致阻变特性的关联，研究薄膜中的电磁耦合现象，揭示其电致阻变特性和磁性调控以及电磁耦合的物理机制，为新型纳米复合电致阻变薄膜的设计制备及进一步的存储器应用奠定良好的基础。

本项目通过研究纳米复合尖晶石铁氧体薄膜的组成和微结构、表面界面结构，并考虑到尖晶石铁氧体材料的结构特殊性，通过有效的掺杂改性、缺陷形成与控制和优化的界面结构设计，探讨了温度、电场和磁场作用下载流子的输运特性、磁性与电致阻变特性的关联，研究了薄膜中的电磁耦合现象，对纳米复合尖晶石结构铁氧体薄膜的电致阻变特性的物理机制有了更深刻的认识。本课题的研究为新型纳米复合电致阻变薄膜的设计制备及进一步的存储器应用提供了新的思路和实验借鉴。.研究结果已在Appl. Phys. Lett.,Adv. Electron. Mater., J. Alloys Compds.等国际学术刊物上发表论文22篇，获授权发明专利1件。已发表论文被Adv. Mater., APL, Nanao Energy, ACS Appl. Mater. Interfaces等正面他引。在国际学术会议上作特邀报告1次。培养博士毕业或在读博士生3人，硕士毕业或在读硕士生4人。指导的部分博士生、硕士生已先后获得研究生国家奖学金、全国电介质物理、材料与应用学术会议优秀墙报奖。