Analysis of a Zirconium Diboride Single Crystal, ZrB2 (0001), by XPS

Abstract

X-ray photoelectron spectroscopy (XPS) was used to study the clean surface of ZrB2 (0001). The clean surface exhibits Zr 3d5/2 and Zr 3d3/2 peaks at 179.2 and 181.6 eV, respectively. However, angle resolved XPS indicated ZrO2 peaks at 183.5 and 185.7 eV at higher emission angles, indicating that further cleaning was necessary. After additional cleaning cycles, these oxide peaks were no longer observed at high emission angles. This result demonstrates the necessity to probe the near surface region with higher emission angles on very reactive surfaces, in order to completely establish the cleanliness of the surface.