Lyu Deyuan, Shoup Jenae E, Huang Dingbin, García-Barriocanal Javier, Jia Qi, Echtenkamp William, Rojas Geoffrey A, Yu Guichuan, Zink Brandon R, Wang Xiaojia, Gopman Daniel B, Wang Jian-Ping
Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Adv Funct Mater. 2023 May;23(18). doi: 10.1002/adfm.202214201.
As a promising alternative to the mainstream CoFeB/MgO system with interfacial perpendicular magnetic anisotropy (PMA), 1-FePd and its synthetic antiferromagnet (SAF) structure with large crystalline PMA can support spintronic devices with sufficient thermal stability at sub-5 nm sizes. However, the compatibility requirement of preparing 1-FePd thin films on Si/SiO wafers is still unmet. In this paper, we prepare high-quality 1-FePd and its SAF on Si/SiO wafers by coating the amorphous SiO surface with an MgO(001) seed layer. The prepared 1-FePd single layer and SAF stack are highly (001)-textured, showing strong PMA, low damping, and sizeable interlayer exchange coupling, respectively. Systematic characterizations, including advanced X-ray diffraction measurement and atomic resolution-scanning transmission electron microscopy, are conducted to explain the outstanding performance of 1-FePd layers. A fully-epitaxial growth that starts from MgO seed layer, induces the (001) texture of 1-FePd, and extends through the SAF spacer is observed. This study makes the vision of scalable spintronics more practical.
作为具有界面垂直磁各向异性（PMA）的主流CoFeB/MgO系统的一种有前景的替代方案，具有大晶体PMA的1-FePd及其合成反铁磁体（SAF）结构可以支持在亚5纳米尺寸下具有足够热稳定性的自旋电子器件。然而，在Si/SiO晶圆上制备1-FePd薄膜的兼容性要求仍未得到满足。在本文中，我们通过用MgO(001)籽晶层覆盖非晶SiO表面，在Si/SiO晶圆上制备了高质量的1-FePd及其SAF。制备的1-FePd单层和SAF堆叠分别具有高度的（001）织构，表现出强PMA、低阻尼和可观的层间交换耦合。进行了包括先进的X射线衍射测量和原子分辨率扫描透射电子显微镜在内的系统表征，以解释1-FePd层的优异性能。观察到一种从MgO籽晶层开始的完全外延生长，诱导了1-FePd的（001）织构，并延伸穿过SAF间隔层。这项研究使可扩展自旋电子学的愿景更加切实可行。
