宽温域跨室温磁斯格明子材料的发现及器件研究  

Observation of new-type magnetic skymrions with extremerely high temperature stability and fabrication of skyrmion-based race-track memory device

作　　者：侯志鹏 丁贝 李航 徐桂舟 王文洪[1] 吴光恒[1] Hou Zhi-Peng;Ding Bei;Li Hang;Xu Gui-Zhou;Wang Wen-Hong;Wu Guang-Heng(State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;University of Chinese Academy of Sciences, Beijing 100049, China;School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, 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]中国科学院大学,北京100049 [3]南京理工大学材料学院,南京210094

出　　处：《物理学报》2018年第13期235-243,共9页Acta Physica Sinica

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:11604148);中国科学院重点研究计划(批准号:KJZD-SW-M01)资助的课题~~

摘　　要：报道了阻挫型磁体Fe_3Sn_2单晶中宽温域跨室温磁斯格明子的发现及其"赛道型"微纳器件的初步探索.通过合金化设计和实验,突破晶体取向生长和克服包晶反应两个关键技术难关,制备出了高质量的Fe_3Sn_2单晶.原位洛伦兹电子显微镜结果表明,在该材料体系中,磁斯格明子具有多种拓扑结构,并可以在一定磁场下相互转化.基于高质量的Fe_3Sn_2单晶,利用聚焦离子束技术,进一步制备出了600 nm宽并具有磁斯格明子单链排列的"赛道性"微纳器件.实验结果表明,该单链磁斯格明子具有极高的温度稳定性:单个磁斯格明子的尺寸以及相邻两个磁斯格明子之间的距离可以在室温到630 K宽温区内保持不变.宽温域跨室温磁斯格明子材料Fe_3Sn_2的发现及单链"赛道型"微纳器件的成功制备,从材料和器件两个方面推进了磁斯格明子材料的实用化.Nanoscle magnetic skyrmions are topologically protected vortex-like spin textures that have been regarded as a promising candidate for the transport of information in further spintronic applications based on the racetrack memory concept due to their nanoscale dimension, stable particle-like feature, and an ultralow threshold for current-driven motion. Recently, most of the skyrmions are observed in chiral magnetic materials, such as Mn Si, Fe Ge, Co-Mn-Zn,where the Dzyaloshinskii-Moriya interaction is active. However, their overall low thermal stability is one of the major factors hindering the practical applications. In this paper, we report the observation of a new-type magnetic skyrmion with extremerely high temperature stability in the centrosymmetric frustrated magnet Fe_3Sn_2, and the fabrication of skyrmion-based race-track memory device based on Fe_3Sn_2 by using focused ion beam. This compound is a rare example of ferromagnetic frustrated magnet that exhibits a high Curie temperature Tc up to 640K. As the temperature decreases from 640K to 100K, it undergoes a spin reorientation during which the easy axis rotates gradually from the c-axis to the ab-plane. The Fe_3Sn_2 has a layered rhombohedral structure with the alternate stacking of the Sn layer and the Fe-Sn bilayer along the c-axis. By a high-temperature flux method, we grow high-quality Fe_3Sn_2 single crystal.The in-situ Lorentz transmission electron microscopy（LTEM） observations demonstrate that this compound can host skyrmions at room temperature（RT）. In contrast to the skyrmions of the chiral magnets, they possess various spin textures and are transformed from topologically trivial bubbles under a high external magnetic field of 800m T. By using the FIB technique, we fabricate a geometrically confined nanostripe with a width of 600nm and thickness of 250nm. The in-situ LTEM observations demonstrate that a single chain of skyrmions with uniform spin textures can be created at RT. The investigations on the temperature stability of the sing

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：O482.54[一般工业技术—材料科学与工程]