Theoretical and experimental study of resonant 3d X-ray photoemission and resonant L3M45M45 Auger transition of PdO

The observed 3d X-ray photoemission spectra (XPS), resonant 3dXPS (RXPS) at the L-3 edge and resonant L3M45M45 Auger electron spectra (RAES) of 4d tra nsition metal oxide PdO are successfully analyzed by means of an impurity A nderson model. The importance of Pd 4d-O 2p hybridization effect is especia lly emphasized in the interpretation of observed spectra. It causes charge transfer satellites in 3dXPS and L(3)M(45)M(45)RAES and mainly determines t he structure of resonance enhancements in 3dRXPS. From the analysis of spec tra, 4d - 2p charge transfer energy Delta; 4d correlation energy U-dd and 4 d - 2p transfer integral pda are estimated to be 5.5 eV, 4.5 eV and 2.1 eV, respectively. The character of the insulating energy gap of PdO is also th eoretically investigated: PdO is classified as an intermediate-type insulat or due to the strong 4d - 2p hybridization.