柔性磁致伸缩FeGa纳米点阵中涡旋态的应力调控研究

项目名称： 柔性磁致伸缩FeGa纳米点阵中涡旋态的应力调控研究

项目编号： No.61504052

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 代国红

作者单位： 南昌大学

项目金额： 21万元

中文摘要： 近年来，磁性纳米点阵中的涡旋态引起了国内外研究人员的广泛关注，研究磁涡旋态不仅对自旋电子学的发展有重要的科学意义，而且在开发下一代高密度磁存储器方面具有广阔的应用前景。 涡旋态发生极性翻转时需要克服的势垒高达十几个电子伏特，以至于无法实现低磁场下的翻转。 通过形状各向异性和应力对磁性纳米点阵中涡旋态进行调控，有望降低涡旋核极性翻转势垒。 应力场可以改变涡旋态的磁结构，与磁场不同的是，应力在材料中产生的退磁场小。因此，应力对磁涡旋态的调控规律将与磁场有显著区别。本项目拟在柔性衬底上制备磁致伸缩FeGa纳米点阵，通过控制纳米点的几何形状并考虑到应力分布，研究应力作用下涡旋态手性和极性的调控规律，并有望实现低场下涡旋态极性的翻转。 通过微磁学模拟计算，阐明应力对涡旋态翻转的动力学行为的调控机制。 该项目研究对于开发基于涡旋态的随机存储器具有一定的参考意义。

中文关键词： 高密度存储器；磁涡旋态；应力；磁致伸缩

英文摘要： The vortex states in magnetic nanodots have recently attracted great attention not only for their scientific significance in spintronics but also for the wide application to the development of next generation high density magnetic storage. During polarization switching of vortex states, the energy barrier to be overcome is as high as over ten eV so that it is hardly to realize the switching at low fields. For magnetic nanodots, their vortex core polarization switching energy barrier could be lowered by adjustment of geometrical shape anisotropy or application of external stress. The stress can change the magnetic structure of vortex state and produce much less demagnetic field than magnetic field. Therefore, the mechanism for stress tuned vortex state will differ from that by using magnetic field. In this project, we plan to fabricate magnetostrictive FeGa nanodots onto flexible substrate. With the consideration of geometrical shape and stress distribution, we will investigate the stress-controlled vortex polarization switching process by magnetic force microscopy, which may achieve switching under very low magnetic field. Using micromagnetic simulation we will clarify the mechanism of vortex polarization switching dynamics under stress field. This study will contribute the development of vortex random access memory devices.

英文关键词： high-density storage;magnetic vortex;stress;magnetostrictive