Surface spectroscopy studies of the SrTiO3(100) surface and the platinum-SrTiO3(100) interface

Auger-electron spectroscopy (AES), low-energy-electron diffraction (LEED), electron-energy-loss spectroscopy (ELS), and ultraviolet-photoelectron spectroscopy (UPS) were used to characterize the composition, structure, and electronic properties of the strontium-titanate (100) surface and the platinum—strontium-titanate interface. The strontium 65-eV Auger signal on the clean strontium-titanate surface decreases abruptly as the temperature is raised beyond 240°C. Partial ordering occurs when platinum is deposited on the strontium-titanate (100) surface as evidenced by LEED. Platinum appears to remove surface ${\mathrm{Ti}}^{3+}$ by electron transfer from SrTi${\mathrm{O}}_3$ to platinum. These results are discussed in light of the findings in photoelectrolysis and other photocatalytic studies using SrTi${\mathrm{O}}_3$.