Electronic structure of dilute α-phase AgCd alloys from thermoreflectance and XPS measurements

The position of the s, p, and d-like levels (at L) in four different silver—cadmium dilute α-phase alloys is determined with respect to the Fermi level, using thermoreflectance and XPS measurements. The use of an analytical model, previously developed, to fit the thermoreflectance data, allows to determine, with substantially increased accuracy over previous alloy work, the dependence of the relevant optical gaps versus solute concentration. Of particular relevance is the behaviour of the L3L′2(EF) gap which shows at first a slight decrease versus solute concentration. XPS measurements on the same samples are consistent with this behaviour which is the opposite of what is predicted by the rigid band model.