原子氢与金刚石表面的相互作用

STUDIES ON THE INTERACTION OF HYDROGEN ATOMS WITH DIAMOND SURFACE

用高分辨率电子能量损失谱研究了氢原子吸附在金刚石表面的各种振动模式,其中主要是位于360meV处的C—H键的伸长振动和位于160meV处的“剪”振动。用氚原子代替氢原子吸附在金刚石表面,观测到上述振动模式所发生的同位素位移。将金刚石表面加热至900℃后,各种振动模式全部消失,这时吸附氢原子全部脱去,金刚石表面的悬键变成平躺在表面上,导致金刚石表面石墨化。由于石墨化后π-带的作用,在损失谱上出现一个非弹性的、连续的损失峰结构。我们用UPS和AES技术进一步证实了脱氢后金刚石表面的石墨化。

The vibration modes of hydrogen-atom adsorption on the diamond surface were studied with high resolution-electron energy loss spectroscopy. Two main losses were observed at 360 meV and 160 meV. They are assigned to the C-H stretch vibrations and the angle-changing deformation vibrations respectively. Replacing H-atom with D-atom, isotropic shifts were observed in the loss spectra. Heating the diamond surface to 900℃, all of the loss features disappear, but an inelastic continuous loss-structure was observed. Due to H-atom desorp-tion, the dangling-bonds became horizontal bonds on the diamond surface, resulting in the gra-phitization of diamond surface. The appearance of the inelastic continuous loss-structure was the characteristic of graphite π-band. The graphitization of the diamond surface was affirmed further by UPS and AES studies.