垂直磁化的纳米自旋矩微波能量捕获器的制备及性能研究

基于自旋转移力矩效应的自旋矩二极管具有尺寸小、结构简单、频率可调和容易集成等优点，在微波探测领域具有广阔的应用前景。近来，理论研究表明自旋矩二极管可以将不同频率的微波能量转换为直流能量（电压），用于微波能量的收集。目前尚未见该方面的实验报道。本项目提出一种基于垂直磁各向异性材料的磁性隧道结多层膜结构，制备基于该结构的纳米自旋二极管器件，研究器件的微波能量收集特性，重点研究垂直磁晶各向异性场、微波频率和功率、外加磁场对整流电压和转换效率的影响。结合微磁学模拟研究微波能量作用下自旋矩二极管的磁动力学行为，并揭示决定器件的微波整流电压和转换效率的关键因素，为开发新型微波能量收集技术做出有益的探索及开拓。

Spin torque diode (STD) based on spin transfer torque effect has attracted intense attention for its potential applications in microwave detecting due to its unique characteristics such as device simplicity, nanoscale size, frequency adjustable, and easy integration. It has recently been shown theoretically, that STDs could play the role of microwave energy harvesters, which can convert microwave signal with different frequency into a direct voltage. Currently, the study of spin microwave energy harvester based STD has not been shown in experiment. This project proposes a novel magnetic tunnel junction (MTJ) multilayer stack using perpendicular magnetic anisotropy materials, and plans to study fabrication and microwave energy harvesting properties of nanoscale MTJs. Particular attention will be paid on the effect of perpendicular magnetic anisotropy, the frequency and power of the microwave energy, and external magnetic field on the rectified d.c. voltage and conversion efficiency. The project will study the magnetization dynamics of STD under microwave energy and reveals the key factors of microwave rectifying voltage and conversion efficiency by combining with micromagnetic simulation. This work is of significance to the development of new microwave energy harvesting from the fundamental and practical view.