Auger and photoemission investigations of the platinum-SrTiO3(100) interface: Relaxation and chemical-shift effects

The energies of the core levels and of the Auger peaks have been measured for the Pt-SrTi${\mathrm{O}}_3$(100) interface with different coverages of platinum. By comparing the core level and Auger chemical shifts for Pt, the changes in the total relaxation energy was obtained with different coverages of platinum. The chemical shift found for Pt-$4f$ peaks, after taking into account relaxation energy, indicates transfer of charge on the order of 0.6 electron/Pt atom from SrTi${\mathrm{O}}_3$ to platinum.