RAMAN-SCATTERING FROM THE MISFIT-LAYER COMPOUNDS SNNBS3, PBNBS3, AND PBTIS3

Raman-scattering experiments have been carried out on misfit-layer com pounds MTS3 (M = Sn, Pb; T= Nb, Ti), in which two types of building la yers, MS and TS2, are sacked alternately. The spectra obtained from th ese compounds are regarded as the superposition of the intralayer vibr ations of individual layers, which indicates a weak interlayer interac tion. The observed Raman shift of the intralayer of NbS2 relative to t hose of 2H-NbS2 is interpreted in terms of a charge transfer from the MS layer to the NbS2 layer.