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采用基于密度泛函的分子动力学赝势方法, 对ZnO在a-Al2O3(0001)表面的吸附进行了理论计算, 研究了ZnO分子在Al2O3表面吸附成键过程、吸附能量与成键方位、表面原子结构变化以及表面化学键特性. 结果表明ZnO在表面吸附后消除了吸附前表面Al-O层的弛豫, 化学结合能为434.3(±38.6)kJ·mol-1. 吸附后ZnO化学键(0.185±0.01 nm)与最近邻的表面Al-O键有30的偏转角度, Zn在表面较稳定的化学吸附位置正好偏离表面O的六角对称约30. 通过吸附前后原子布居数、态密度以及成键电子密度的分析, 表明ZnO的O2-与表面上的Al3+所形成的化学键具有强离子键特征; 而Zn2+同基片表面O2- 形成的化学键有明显的共价键成分, 主要来自于Zn 4s与O 2p的杂化, 以及部分Zn 3d与O 2p的杂化.
Adopting density functional theory-based molecular dynamics pseudopotential method, the adsorption of ZnO on a-Al2O3 (0001) surface has been theoretically calculated. The adsorption process of ZnO on Al2O3 surface, the adsorption energy and bond orientation, the surface Atomic structure and surface chemical bond.The results show that the surface relaxation of the Al-O layer before adsorption is abolished by ZnO, the chemical binding energy is 434.3 (± 38.6) kJ · mol-1. The ZnO chemical bond (0.185 ± 0.01 nm) and the nearest neighbor Al-O bond has a deflection angle of 30, Zn in the surface more stable chemical adsorption position just offset from the surface of the hexagonal symmetry of O. By atomic absorption before and after population, state density and bonding The analysis of electron density shows that the chemical bond formed by the O2- of ZnO and the Al3 + on the surface has a strong ionic bond. The chemical bond formed between Zn2 + and the surface of O2- has obvious covalent bond, which mainly comes from Zn4s and O 2p hybridization, and some Zn 3d and O 2p hybridization.