Synchrotron radiation photoemission has been used to study the formation of
Sm overlayer on the surface of CdTe( 100) crystal. The data were recorded
at room temperature for Sm coverage ranging from 0 to 9 ML. The analysis of
constant initial state spectra and energy distribution curves taken in the
valence band region showed that at very low Sm coverage (0.1 and 0.2 ML) t
he trivalent Sm state dominates. For higher coverages the average valence o
f the system drops down from the value of 2.7 to 2.2 for 1.8 NIL. The analy
ses of Sm4f multiplet peaks binding energy lead to the conclusion that the
average valence of Sm in the Sm/CdTe(100) system is heterogeneous (the vale
nce has site-dependent but integer value). The photoemission results indica
te strong Sm-CdTe interaction and confirm the assumption about the creation
of a surface compound with spinel CdSm2Te4 structure. (C) 2001 Elsevier Sc
ience B.V. All rights reserved.