Conduction Properties of Incommensurate Misfit Layer Compounds (CeS)1.19(TiS2)n(n=1,2)

Abstract

We investigated transport properties for incommensurate misfit layer compounds (CeS) 1.19 (TiS 2 ) n ( n =1,2) with stage-1 and stage-2 structures. Both materials showed metallic conduction. The Hall effect showed that the electrical conduction is dominated by the electron carriers for both compounds, while thermoelectric power of stage-1 (CeS) 1.19 TiS 2 had a positive value of +5 µV/K at room temperature. This proved that the two different energy bands overlap at E F of stage-1 (CeS) 1.19 TiS 2 . Detailed analysis of the thermoelectric power revealed the existence of short range domain-boundary phonon scattering process, where the mean free path is estimated to be of the order of 10 Å. This means that the local-lattice modulation induced by the incommensurate structure has a remarkable effect on the scattering process of the acoustic phonons as well as the conduction electrons.