NEW ASPECTS OF THE DEEXCITATION MECHANISM IN AUGER-ELECTRON APPEARANCE-POTENTIAL SPECTROSCOPY

Contributions of electrons with different energies to Auger electron a ppearance potential spectroscopy (AEAPS) have been investigated. Appea rance potential spectra amplitude dependences have been measured for T i, Cr, Mn and Ni by means of a previously exploited method using a sph erical three-grid retarding field system. The effective dimensionless coefficient sigma(eff), representing the number of slow electrons emit ted at the disappearance of one elastically reflected electron at a th reshold potential, ranges from 2.7 to 3.5 for L-2,L-3 subshells and fr om 9 to 11 for L-1 subshells. These results have been accounted for in terms of fast, highly probable Coster-Kronig transitions which turned out to be the only possibility for relaxation of the L-1 subshells of the materials under investigation. This explanation has been supporte d by a direct comparison with both former and recent experimental resu lts. (C) 1997 Elsevier Science B.V.