Reflectivity spectra of some first row transition metal intercalates of NbS2

Abstract

The room temperature reflectivities from the basal planes of the first row transition metal intercalation compounds Mn_0·26NbS₂, Fe_0·33NbS₂, Co_0·32NbS₂, and Ni_0·34NbS₂ have been measured in the energy range 25 meV to 6 eV. The transition metal concentrations have been determined by electron beam microprobe analysis. The changes in the reflectivity spectra of NbS₂ after intercalation have been interpreted in terms of a rigid band model and charge transfer from the ionized intercalate to the host NbS₂ d_z ² conduction band. The reflectivities in the region of the Drude edge have been fitted by a theoretical model from which the optical parameters appropriate to this edge have been obtained