低损耗亚微米级微波单晶石榴石薄膜及自旋应用基础研究

项目名称： 低损耗亚微米级微波单晶石榴石薄膜及自旋应用基础研究

项目编号： No.51472046

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 杨青慧

作者单位： 电子科技大学

项目金额： 83万元

中文摘要： 近期，低损耗亚微米厚度的微波石榴石单晶薄膜成为自旋电子学领域需求与研究的热点。要实现自旋电流的长距离传输和调控，低损耗石榴石单晶薄膜是目前为止最好的选择。但目前对于自旋器件中应用的亚微米低损耗微波单晶薄膜的研究一片空白。因此本课题首先建立YIG单晶薄膜上自旋电流传导与输运模型，对几百纳米下薄膜体系的损耗进行设计模拟；其次着力于解决降低液相外延工艺中的转换层厚度：从探索液相外延的生长机理出发，控制熔体过冷度，增加相变驱动力，促进材料的快速成核，从而降低转换层厚度；然后控制熔体中石榴石粒子对基片的碰撞和熔体的析出，并控制熔体与衬底之间的润湿性，获得极高的表面平整度；最后，通过理论和实验调整配方，设计分凝系数和外延参数，控制Pb2+-Pt4+离子团的出现，成功制备出低损耗亚微米厚度单晶微波薄膜。

中文关键词： 亚微米；低损耗；单晶薄膜；自旋传导

英文摘要： Recently, the sub-micrometer single garnet crystal film with low loss has been required in spin-wave field. If we want to realized the long distance propagation and modification of spin current, the pure YIG film with low loss is the best choice. But there is no investigation about this kind of film. Firstly, the model of spin current propagation in garnet film will be created and caculate the loss in single crystal film with hundrends of nanometer thickness; Secondly, the thickness of tansfer layer between film and substrate will be decreased based on liquid phase epitaxy growth thoery, supercooling of flux, driving force of growth and quickly nucleation.Thirdly, the collision of garnet particles to substrate, flux separation out and wettability will be controlled to get the mirror surface; Finnally, the Pb2+-Pt4+ ionic groups will be restrained by liquid phase epitaxy technology and composition of flux to obtain the low loss single crystal film with sub-micrometer thickness.

英文关键词： sub-micrometer;low loss;single crystal film;spin-wave propagation