Okotrub Alexander V, Sedelnikova Olga V, Gorodetskiy Dmitriy V, Fedorenko Anastasiya D, Asanov Igor P, Palyanov Yury N, Lapega Alina V, Gurova Olga A, Bulusheva Lyubov G
Nikolaev Institute of Inorganic Chemistry SB RAS, 630090 Novosibirsk, Russia.
Sobolev Institute of Geology and Mineralogy, 630090 Novosibirsk, Russia.
Materials (Basel). 2023 Feb 16;16(4):1650. doi: 10.3390/ma16041650.
Diamond is an important material for electrical and electronic devices. Because the diamond is in contact with the metal in these applications, it becomes necessary to study the metal-diamond interaction and the structure of the interface, in particular, at elevated temperatures. In this work, we study the interaction of the (100) and (111) surfaces of a synthetic diamond single crystal with spattered titanium and molybdenum films. Atomic force microscopy reveals a uniform coating of titanium and the formation of flattened molybdenum nanoparticles. A thin titanium film is completely oxidized upon contact with air and passes from the oxidized state to the carbide state upon annealing in an ultrahigh vacuum at 800 °C. Molybdenum interacts with the (111) diamond surface already at 500 °C, which leads to the carbidization of its nanoparticles and catalytic graphitization of the diamond surface. This process is much slower on the (100) diamond surface; sp-hybridized carbon is formed on the diamond and the top of molybdenum carbide nanoparticles, only when the annealing temperature is raised to 800 °C. The conductivity of the resulting sample is improved when compared to the Ti-coated diamond substrates and the Mo-coated (111) substrate annealed at 800 °C. The presented results could be useful for the development of graphene-on-diamond electronics.
金刚石是电气和电子设备的重要材料。由于在这些应用中金刚石与金属接触，因此有必要研究金属 - 金刚石相互作用以及界面结构，特别是在高温下。在这项工作中，我们研究了合成金刚石单晶的（100）和（111）表面与溅射的钛和钼薄膜的相互作用。原子力显微镜显示钛的均匀涂层以及扁平钼纳米颗粒的形成。薄钛膜在与空气接触时完全氧化，并在800°C的超高真空中退火时从氧化态转变为碳化物态。钼在500°C时就与（111）金刚石表面相互作用，这导致其纳米颗粒的碳化和金刚石表面的催化石墨化。在（100）金刚石表面上这个过程要慢得多；只有当退火温度升至800°C时，在金刚石和碳化钼纳米颗粒顶部才会形成sp杂化碳。与涂钛金刚石基板和在800°C退火的涂钼（111）基板相比，所得样品的导电性得到了改善。所呈现的结果可能对金刚石上石墨烯电子学的发展有用。
