Spectator Auger transitions of the 1s hole states in ionic sulfur compounds and molecular chlorine compounds

The Auger transitions after resonant S1s --> 3p* (3p* indicates unoccupied states with 3p character) and Cl1s --> 3p* excitations were studied for sulfur compounds (MoS2, Li2SO4 and Na2S2O3) and chlorine compounds (Si(CH3)3Cl and SiCl4 solidified on Cu(100) surface) by photoemission spectroscopy using synchrotron radiation. In the photon energy of the resonant excitations, the KL2,3L2,3 spectator Auger line was found to shift in two steps to higher electron energy by 2 - 10 eV in proportion to the exciting photon energy. Furthermore conspicuous splitting of the Auger line into a two-peak structure was found for Li2SO4, Na2S2O3 and multilayered chlorine compounds. The phenomena observed for these insulators indicate that both screening effect in the decay process and broad bandlike structures of the unoccupied states play important roles in the Auger resonant Raman scattering of the incident photons.