磁性绝缘体二维微纳结构的构筑及其微波磁学研究

The two-dimentional micro-nano structures based on the magnetic insulator thin films have significant promising applications in magnonics and novel spin-wave devices. For the purpose to build the novel microwave photon-magnon coupling system, the preparation of the high-quality BaM hexaferrite epitaxial films and the 2D micro-nano structures will be studied symmetrically. The technical path to the the low Gilbert damping constants of the ferrite films will be established by investigation on the influences of compositions, interfacial structures and processing controlling, and the underlying mechanisums for the low damping will be revealed by the microwave and magnetic characterization techniques. The phonon-magnon coupling systems will be constructed by the planar-geometry resonator-ordered magnetic structures hybrids on low-damping magnetic insolator films. The metasurfaced resonators will be act as the high-Q resonators in the novel coupling systems in order to enhance the coupling strength, and the couping mechanisms will be investigated. The novel magnetic micro-nano structures will be obtained on ferrite films via nano-patterning and epitaxial growth process. The microwave magnetics, such as magnetization dynamics and ferromagnetic resonatance behaviors as well as the spin-wave excitation and modulation will be studied symmetrically. The experimental data and theoretical results obtained in this project will support for the development of the novel spin-wave based microwave and millimeter-wave devices.

基于磁性绝缘体薄膜的二维有序微纳结构在磁振子晶体和新型自旋波器件方面有重要的应用前景，本项目旨在以构建新型微波光子-磁振子耦合体系为目标，系统研究高质量BaM磁性绝缘体薄膜的外延生长及其二维有序微纳结构的制备技术，通过薄膜的组成、界面结构和制备工艺控制等探求降低薄膜磁阻尼因子的技术途径和机制，利用平面介质谐振器与磁性有序微纳结构的结合，实现磁性薄膜中微波光子与磁振子强耦合作用，深入研究微波光子与磁振子之间相互耦合机制，探求提高耦合强度的方法，并结合铁氧体薄膜的纳米图形化技术及外延生长工艺，获得新型的磁性有序结构，进而研究自旋波的激励、调制及其微波动态响应机制，为发展基于自旋波的新型微波毫米波磁学器件提供理论和实验依据。

基于磁性绝缘体薄膜的二维结构在新型自旋波器件方面有重要的应用前景，本项目以探索面向自旋波器件应用的新型微波电磁材料为目标，围绕磁性绝缘体二维结构的制备及其微波与磁学性能开展了系统研究，研究内容包括: 高质量磁性绝缘体薄膜的制备与表征、磁性微纳点阵结构的制备及其微波动态响应、微波光子高频吸收机理及低损耗介质材料研究、微波光子-磁振子二维结构的构筑及其强耦合作用。取得的重要成果包括：采用磁控溅射制备技术成功制备出高质量面外取向BaM和YIG铁氧体薄膜，BaM铁氧体薄膜具有较强的磁晶各向异性，其零场铁磁共振频率约35GHz，YIG铁氧体薄膜其铁磁共振线宽约为2Oe，接近YIG单晶薄膜；利用超薄AAO掩膜版在YIG薄膜上制备出一种新颖的YIG/BaM纳米点阵结构；通过太赫兹时域谱揭示了微波光子高频吸收机理，并通过缺陷控制等制备出多种超低损耗的微波和毫米波介质基板材料；利用平面谐振器与铁氧体薄膜组合，构筑出响应频率分别在微波和毫米波段的微波光子-磁振子平面化耦合系统，观测到微波光子与磁振子的强耦合现象及自旋波传输信号，并揭示了强耦合作用的机理。本项目研究成果为进一步发展微波光子-磁振子混杂耦合体系及新型自旋波器件提供了理论和实验依据。