铁磁/介电复合材料的微波磁导率新型电极化调控

In this project, in order to develop novel coupling between electric and magnetic materials, it need to solve one important issue: the coupling between polarization and magnetization (P&M coupling) induced microwave magnetic permeability. Based on this case, we would investigate design and fabrication soft magnetic materials with high permeability under high frequency deposited dielectric substrate, and investigate P&M induced micrwowave magnetic permeability in magnetic materials. In theory, based on Landau-Lifshitz-Gilbert（LLG）equaion, the physical mechanism of changing of P&M induced static and micrwowave magnetic properties are investigated in details. In experiment, we would fabricate ferromagnet/dielectric nanocomposited film to understand the effect of different spin polarization,spin diffusion length and magnetic anisotropy distribution on P&M coupling, respectively. In measuring method, based on electromagnetic wave transmission theory, we would develop a measurement of GHz complex permeability under in-situ different polarization, which reflect the change of nature microwave magnetic properties. It is therefore desirable to understand the mechanism of changing of microwave magnetic properties by P&M coupling and provide a possible to develop new functional magnetic devices and optical devices, which advance electronic information technology development.

本项目围绕新型电磁耦合机制的探索，电极化强度和磁化强度P&M耦合调控磁性材料微波磁导率的新原理这一关键科学问题，重点研究高频高磁导率软磁材料/介电衬底异质纳米结构薄膜的设计与制备，通过P&M耦合调控磁性材料的微波磁导率，从理论上探讨微波下P&M耦合调控磁导率的物理机制；材料上基于异质纳米结构中的复合，研究不同自旋极化率、自旋散射长度以及各向异性分布的磁性材料对P&M耦合强度的影响；测量上基于电磁波传输理论，发展一种可以原位变化电极化强度的磁谱测量，可以更精确的测量在不同微波频率下对磁性材料磁导率影响。通过项目的研究不仅有助于理解P&M耦合调控软磁材料微波磁导率的物理机制，同时也为突破传统磁性器件、光学器件的功能化提供了可能，这对电子信息技术的发展有重要意义。

项目围绕新型电磁耦合机制的探索，电极化强度和磁化强度P&M耦合调控磁性材料微波磁导率的新原理这一关键科学问题，研究了软磁材料/介电衬底异质纳米结构薄膜的设计与制备，通过P&M耦合调控磁性材料的微波磁导率，理论上探讨微波下耦合的物理机制，提出了自旋屏蔽的磁子效应，材料上研究了不同散射长度，不同厚度的磁性材料，进一步说明了耦合长度与自旋散射长度的关系，测量上实验原位的电极化调控的微波测量，并通过布里渊散射测量了电场下磁子的行为变化，进一步证明了自旋屏蔽的磁子效应对磁性的影响。通过项目的研究不仅实现对P&M耦合调控磁导率的物理机制的理解，同时也突破传统器件、光学器件的功能化给出应用前景，对电子信息技术的发展有重要意义。在本项目的资助下，在Phys. Rev. B (Rapid Communication), Phys. Rev. Applied, Adv. Funct. Meter., Appl. Phys. Lett.等杂志发表SCI论文20篇，培养研究生6名，其中毕业博士3人，毕业硕士3人，1人获得甘肃省优秀博士论文，1人获得甘肃省优秀硕士论文。