高温度稳定性磁斯格明子的材料发现及性能调控  

Discovery of high temperature magnetic skyrmions and current-induced helicity reversal in a nanostructured frustrated magnet

作　　者：侯志鹏 王文洪[1] 吴光恒[1] HOU Zhi-Peng;WANG Wen-Hong;WU Guang-Heng(Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;Guangdong Provincial Key Laboratory of Optical Information Materials and Technology&Institute for Advanced Materials,South China Academy of Advanced Optoelectronics,South China Normal University,Guangzhou 510006,China)

机构地区：[1]中国科学院物理研究所磁学国家重点实验室,北京100190 [2]华南师范大学先进材料研究所,广州510006

出　　处：《物理》2020年第2期84-90,共7页Physics

基　　金：国家重点基础研究发展计划(批准号:2017YFA0303202);国家自然科学基金(批准号:11974406)资助项目;国家自然科学基金青年项目(批准号:51901081);中国科学院重点部署项目(批准号:KJZD-SW-M01)。

摘　　要：文章报道了阻挫型磁体Fe3Sn2中高温度稳定性磁斯格明子材料的发现以及利用电流实现斯格明子自旋手性翻转的一系列工作。作者首先基于合金化设计的思想,解决了晶体取向生长困难和易发生包晶反应这两个关键技术难题,生长出了高质量的Fe3Sn2单晶样品。通过原位洛伦兹电镜观测发现,该材料体系具有室温磁性斯格明子,并具有多种拓扑形态,而且在外部磁场作用下可以相互转化。作者进一步利用聚焦离子束(FIB)技术,采用空间几何受限方法,制备出了磁斯格明子单链排列的“赛道”纳米条带样品。实验发现,该样品中斯格明子可以在室温到630 K极宽温区内保持其尺寸及间距不变,这表明该材料中斯格明子具有极高的温度稳定性。在这些研究工作基础上,作者在“赛道”纳米条带样品中进一步实现了电流驱动的斯格明子自旋手性翻转。作者这一系列关于高温度稳定性磁斯格明子材料以及相关器件的探索工作,从材料和器件两个方面推进了磁斯格明子材料的实用化。Skyrmionic spin configurations have attracted considerable attention for their intriguing magneto-electrical properties.Here,we report the observation of frustrated magnetic skymrions with extremely high temperature stability in the magnetic alloy Fe3Sn2,and also the fabrication of skyrmion-based race-track memory devices.In this compound,the magnetic skyrmions possess various spin textures and can transform into each other under certain external magnetic fields.Furthermore,by using focused ion beam technology,a single skyrmion chain was fashioned into a geometrically confined race-track shape Fe3Sn2 nanostripe with a width of 600 nm.It was found that this single chain has extremely high temperature stability,and the size and interspacing of the skyrmion bubbles remain unchanged from room temperature up to a record-high 630 K.We also observed the current-induced helicity reversal of Bloch-type skyrmions in a nanostructured Fe3Sn2 frustrated magnet.The critical pulse current density required to trigger the helicity reversal is 109-1010 A/m2 with a corresponding pulse-width range of 1μs-100 ns.Our realization of this new type of extremely stable magnetic skymrion and the fabrication of skyrmion-based race-track memory devices represent important steps towards the application of skyrmion-based spintronic devices.

关 键 词：磁斯格明子 阻挫型磁体 室温宽温域 “赛道”型存储器 

分 类 号：O469[理学—凝聚态物理]