4D CORE-LEVEL RESONANT PHOTOEMISSION SPECTROSCOPY OF THULIUM MONOCHALCOGENIDES AROUND THE TM 3D THRESHOLD

We report the results of 4d core-level photoemission spectra for thuli um monochalcogenides, TmX (X = S, Se, Te) around the 3d-4f absorption edge. The resonance effect for Tm 4d emission occurs through partial d ecay channels of the 3d-4f excited states. The lifetime-broadening phe nomenon, which depends strongly on the binding energy, is also employe d here for elucidation of 4d photoelectron spectral features. The beha vior of a particular decay channel, referred to as 3d-4d4f, followed b y preferential excited states was studied extensively. (C) 1998 Elsevi er Science B.V.