摘要
Co/Pt多层磁性薄膜具有良好的垂直磁各向异性等优点,已经广泛应用于畴壁移动自旋器件、磁性斯格明子/自旋轨道矩等自旋电子学领域。然而,目前的研究还极少关注多层膜中微观结构与其宏观磁性产生之间的深层关系。本文以Co/Pt/Ta多层膜为对象,将透射电镜的二次电子成像(STEM-SEI)和几何相位分析(GPA)技术相结合,对多层膜层间界面微观结构、应力及其与宏观磁性的联系开展了系统和多维度表征。结果表明:STEM-HAADF/BF等不同衬度成像说明Co/Pt/Ta多层膜界面清晰,与预期设计吻合;结合STEM-BEI/SEI表明,该多层膜表面平整、成膜性良好;VSM测试证实多层膜具有典型垂直各向异性与优良磁学性能;GPA技术定量确定了多层膜内存在大量微观应力,解释了HRTEM黑色衬度源于晶格失配应力。上述结果揭示了多层膜宏观磁滞回线与微观应变之间存在直接关联的结构层面证据,为理解及开发新型低功耗自旋电子器件在微观结构角度提供新证据和新见解。
Co/Pt multilayer magnetic films,with advantages such as excellent perpendicular magnetic anisotropy,have been widely applied in spin-electronics fields,including spin-torque devices with domain-wall motion and magnetic skyrmions/spin-orbit torque-based devices.However,currently,little attention has been paid to the in-depth relationship between the micro-structure of Co/Pt multilayer films and the origin of their macroscopic magnetism.In this study,Co/Pt/Ta multilayer films were systematically and multidimensionally characterized using transmission electron microscopy(TEM)-based secondary electron imaging(STEM-SEI)and geometric phase analysis(GPA)to investigate the interlayer interfacial microstructure,stress,and their correlation with macroscopic magnetism.The results show that different contrast imaging techniques(STEM-HAADF/BF)confirm the clear interfaces of the multilayers,consistent with the designed structure.Combined with STEM-BEI/SEI,the smooth surface and excellent film-forming quality of the multilayer films are demonstrated.Vibrating sample magnetometry(VSM)measurements reveal that the multilayer films exhibit typical perpendicular magnetic anisotropy and superior magnetic properties.GPA quantitatively identifies significant micro-stresses within the multilayer films and clarifies that the black contrast in high-resolution TEM(HRTEM)images originates from lattice-mismatch stress.These findings provide direct structural evidence linking the macroscopic magnetic hysteresis loops to micro-strain in multilayer films,offering new insights and evidence from a microstructural perspective for the understanding and development of novel low-power spin-electronic devices.
作者
郭金键
安伊杉
全志勇
GUO Jinjian;AN Yishan;QUAN Zhiyong(Key Laboratory of Magnetism of Ministry of Education,College of Chemistry and Materials Science,Analytical and Testing Center,Shanxi Normal University,Taiyuan 030031,China)
出处
《中国有色金属学报》
北大核心
2025年第8期2763-2771,共9页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(12404231)
山西省青年基金资助项目(202403021222237)
山西省高校科技创新项目(2024L147)。
