声表面波辅助亚铁磁CoTb薄膜中磁畴壁移动-中国材料进展

文章信息/Info

Title:: Surface Acoustic Wave Assisted Magnetic Domain Wall Motion in Ferrimagnetic CoTb Alloy

作者:: 郑文慧1; 2; 边肖南1; 蔺涛1; 曹洋3; 苏丹1; 孙一铭1; 杨德政3; 阎照文2; 雷娜1; （1. 北京航空航天大学集成电路科学与工程学院，北京 100191）（2. 北京航空航天大学电子信息工程学院，北京 100191）（3. 兰州大学磁学与磁性材料教育部重点实验室，兰州 730000）

Author(s):: ZHENG Wenhui1; 2; BIAN Xiaonan1; LIN Tao1; CAO Yang3; SU Dan1; SUN Yiming1; YANG Dezheng3; YAN Zhaowen2; LEI Na1; (1.School of Integrated Circuit Science & Engineering, Beihang University, Beijing 100191, China) (2.School of Electronic and Information Engineering, Beihang University, Beijing 100191, China) (3.Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China）

Keywords:: surface acoustic wave (SAW); ferrimagnetism; CoTb film; coercive field; domain wall motion

摘要:: 利用电压产生的动态应力——声表面波调控材料磁性，具有高效率、低功耗和长传输距离等优点，近年来成为自旋电子学领域研究的热点。亚铁磁材料因其较快的磁畴壁移动速率而深受关注，因此，探究声表面波辅助作用下亚铁磁体系中磁畴壁的移动，对磁存储、磁逻辑等自旋电子器件的研究具有重要意义。以具有垂直磁各向异性的亚铁磁CoTb薄膜作为研究材料体系，制备出声表面波与亚铁磁材料的耦合器件，研究了声表面波对CoTb薄膜矫顽场以及磁畴壁移动的调控效应。实验表明，在声表面波的辅助作用下CoTb薄膜的矫顽场减小了10%。经分析确认，磁畴成核场及磁畴壁传播场的减弱是矫顽场减小的主要原因。此外，利用磁光克尔显微镜观测磁畴壁移动，发现在声表面波的辅助下磁畴壁移动速率提高了约76%，达到3683 μm/s。在亚铁磁材料体系中成功实现声表面波辅助磁畴壁的快速移动，为未来低功耗自旋电子器件发展开辟了新的路径。

Abstract:: Voltage induced surface acoustic wave (SAW) is a hot research topic for manipulating magnetic properties in spintronics, due to its characteristics of high efficiency, low power consumption and long propagation distance. The ferrimagnet has attracted much attentions due to its fast magnetic domain wall (DW) motion. The study of its DW motion assisted by SAW is of great significance for the magnetic memory and DW logic devices. Here, we chose ferrimagnetic CoTb film with perpendicular magnetic anisotropy, and fabricated the coupled device of the SAW and Hall bar structure. The coercive fields and DW motion in CoTb film under SAW are explored by magneto-optical Kerr microscopy. We found the coercive fields reduced by 10% in CoTb film system, which is mainly originated from the reduction of the nucleation and propagation fields under the SAW. Furthermore, we observed the DW motion speed increased up to 76% with the assistance of the SAW, which reached 3683 μm/s. Our work has successfully realized the rapid DW motion driven by SAW in the ferrimagnetic system, which provides an alternative to the future low-consumption spintronic devices.