氧原子在Al(100)、(110)、(111)面上的吸附与振动

利用原子与表面簇合物相互作用的5参数Morse势方法(简称5-MP)系统研究了O-Al低指数面表面吸附体系, 获得了吸附几何、结合能、振动频率等吸附态的临界点特性. 通过把这些临界点特性作为研究吸附体系的探针, 系统分析了吸附体系的性质. 理论计算结果表明, 在Al(111)面上, 氧原子在表面三重位处存在吸附态, 其垂直表面的振动频率为621(619) cm-1, 平行表面的振动频率为880(887) cm-1. 在子表面八面体处也存在吸附态, 其垂直振动频率为464 cm-1, 平行振动频率为437 cm-1; 在Al(100)面上, 氧原子在表面四重洞位、子表面四面体处存在吸附态;在Al(110)面上,氧原子优先吸附在表面膺势三重位而非长桥位,同时子表面八面体处也存在吸附态.

Adsorption and Vibration of Oxygen Atom on A1(100),(110),(111)Planes

Adsorption of O atom on Al low index surfaces was inverstigated with the 5-parameter Morse potential (5-MP). All critical characteristics of this system, such as adsorption site, adsorption geometry, binding energy, and eigenvalue for vibration, were obtained. All critical characteristics were regarded as probe to analysis the adsorption system systematically, the comprehensive adsorption characters were found out. The calculated results showed that O atoms were located at the three-fold hollowsite and the octahedral site of the Al(111) with the perpendicular vibrational mode 621(619) cm-1 and 464 cm-1, the parallel vibrational mode 880 (887) cm-1 and 437 cm-1. For Al(100) system, O atoms were located at the four-fold hollow site and the tetrahedral site. With respect to Al(110) system, the preferential adsorption states were the quasi-3-fold site and the octahedral site rather than the long bridge site.