Wu Ruinan, Hu Yueguo, Li Peisen, Peng Junping, Hu Jiafei, Yang Ming, Chen Dixiang, Guo Yanrui, Zhang Qi, Xie Xiangnan, Dai Jiayu, Qiu Weicheng, Wang Guang, Pan Mengchun
College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, China.
Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha 410073, China.
Nanomaterials (Basel). 2021 Nov 18;11(11):3112. doi: 10.3390/nano11113112.
The strong spin filtering effect can be produced by C-Ni atomic orbital hybridization in lattice-matched graphene/Ni (111) heterostructures, which provides an ideal platform to improve the tunnel magnetoresistance (TMR) of magnetic tunnel junctions (MTJs). However, large-area, high-quality graphene/ferromagnetic epitaxial interfaces are mainly limited by the single-crystal size of the Ni (111) substrate and well-oriented graphene domains. In this work, based on the preparation of a 2-inch single-crystal Ni (111) film on an AlO (0001) wafer, we successfully achieve the production of a full-coverage, high-quality graphene monolayer on a Ni (111) substrate with an atomically sharp interface via ambient pressure chemical vapor deposition (APCVD). The high crystallinity and strong coupling of the well-oriented epitaxial graphene/Ni (111) interface are systematically investigated and carefully demonstrated. Through the analysis of the growth model, it is shown that the oriented growth induced by the Ni (111) crystal, the optimized graphene nucleation and the subsurface carbon density jointly contribute to the resulting high-quality graphene/Ni (111) heterostructure. Our work provides a convenient approach for the controllable fabrication of a large-area homogeneous graphene/ferromagnetic interface, which would benefit interface engineering of graphene-based MTJs and future chip-level 2D spintronic applications.
晶格匹配的石墨烯/Ni(111)异质结构中C-Ni原子轨道杂化可产生强自旋过滤效应，这为提高磁隧道结(MTJ)的隧道磁电阻(TMR)提供了理想平台。然而，大面积、高质量的石墨烯/铁磁外延界面主要受限于Ni(111)衬底的单晶尺寸和取向良好的石墨烯畴。在这项工作中，基于在AlO(0001)晶片上制备2英寸单晶Ni(111)薄膜，我们通过常压化学气相沉积(APCVD)成功地在具有原子级清晰界面的Ni(111)衬底上制备出全覆盖、高质量的石墨烯单层。系统地研究并仔细证明了取向良好的外延石墨烯/Ni(111)界面的高结晶度和强耦合。通过对生长模型的分析表明，Ni(111)晶体诱导的取向生长、优化的石墨烯成核和次表面碳密度共同促成了高质量的石墨烯/Ni(111)异质结构。我们的工作为大面积均匀石墨烯/铁磁界面的可控制备提供了一种简便方法，这将有利于基于石墨烯的MTJ的界面工程和未来芯片级二维自旋电子学应用。
