Abstract
Wurtzite-type ZnO is the polar crystal whose (0001) surface is terminated by Zn ions. The surface structure of ZnO single crystal was investigated by Atomic Force Microscope (AFM), Reflection High-Energy Electron Diffraction (RHEED) method and Coaxial Impact-Collision Ion Scattering Spectroscopy (CAICISS). From AFM observations, the surface had a step/terrace structure and the step height was evaluated as a half of a lattice parameter. In order to remove impurities adsorbed on the surfaces, the samples were heated in an analysis chamber at 900°C for 3 hours under a pressure of 5×10-7 Pa with the irradiation of oxygen radical, and CAICISS and RHEED were observed. It was shown from RHEED patterns that the surface had (1 X 1) structure. From the polar angle dependence of CAICISS-TOF spectra for Zn ions, a peak due to the focusing effect for the 1st to 5th layer of Zn ions was observed at about 2° higher angle than a simulated angle. It could be concluded that the uppermost Zn ions were moved outside of the surface by 7% due to the relaxation.
| Original language | English |
|---|---|
| Pages (from-to) | 221-224 |
| Number of pages | 4 |
| Journal | Key Engineering Materials |
| Issue number | 181-182 |
| Publication status | Published - 2000 Jan 1 |
| Externally published | Yes |
Keywords
- Atomic Force Microscopy
- Coaxial Impact-Collision Ion Scattering Spectroscopy
- Reflection High Energy Electron Diffraction
- Surface Relaxation
- Zinc Oxide
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering