L3M4,5M4,5 SPECTATOR AUGER PROCESSES IN 4D TRANSITION-METAL COMPOUNDS

L3M4, 5M4, 5 spectator Auger processes around 2p3/2(L3) edges were studied for 4d transition metal compounds using synchrotron radiation. We selected metallic substances (Nb, Mo and MoO2) and insulating oxides (Y2O3, ZrO2, Nb2O5 and MoO3) to compare the results. For all the metallic substances, the L3M4, 5M4, 5 spectator Auger peak shifts almost linearly with incident photon energy (h nu) when h nu is adjusted below the absorption, while its kinetic energy is almost constant above the absorption. These behaviors are nearly the same as those observed for the X-rays emitted in the resonant Raman scattering. On the other hand, for all the insulators the L3M4, 5M4, 5 Auger peak is split into spectator and normal Auger peaks above the absorption and that the former peak shifts almost linearly with h nu. The phenomena observed were explained in connection with both screening effect in the decay process and broad band structure of the unoccupied states of the insulators.