CASCADE AUGER TRANSITIONS OF RESONANTLY EXCITED S 1S AND CL 1S HOLES

Anger decay processes of resonantly excited S Is holes and Cl Is holes have been studied for MoS2 and SiCl4 by photoemission spectroscopy using tunable synchrotron radiation. It is clearly shown that the excited states mainly decay via the KL(2,3)L(2,3) and KL(1)L(2,3) spectator Auger transitions. Above the Is absorption edges, two Anger signals were observed for the L(2,3)VV Auger transition. Both of them were resonantly enhanced in the vicinity of the Is absorption edges. The signal of the higher-kinetic-energy side was assigned to the double-ionization satellite originating from the cascade Auger transitions such as KL(1)L(2,3) --> (L(1)L(2,3)V)L(2,3)VV/V)L(2,3) and KL(2,3)L(2,3) --> (L(2,3)VV)L(2,3). The satellite intensity was analysed for the S(L(2,3)VV) Auger line in MoS2, assuming stepwise transitions. The satellite observed was found to have an intensity a third of that expected. The origin of the discrepancy between the experimental and calculated intensities is discussed.