Resonant Auger spectroscopy on SiF4 and SiCl4 molecules excited around the silicon 2p edge

We describe in this paper very recent results obtained by mean of resonant Auger spectroscopy experiments on SiF4 and SiCl4 molecules excited around the silicon 2p edge. Both molecules exhibit participator resonant Auger decay paths never observed in previous measurements. The enhancement of photoelectron lines is interpreted by the silicon character versus the halogeno lone pairs parentage. In contrast with the SiF4 molecule, the SiCl4 molecule reveals a continuous electron background when exciting the two first core to anti-bonding discrete resonances. A possible explanation of the origin of this electron background in terms of an Auger emission perturbed by the nuclear motion is also given. (C) 1998 Elsevier Science B.V. All rights reserved.