CDW GAP EFFECTS ON THE RAMAN SPECTRA IN ORTHORHOMBIC TaS_3(EXPERIMENTS ON MX_3 COMPOUNDS, International Symposium on NONLINEAR TRANSPORT AND RELATED PHENOMENA IN INORGANIC QUASI ONE DIMENSIONAL CONDUCTORS)

Abstract

Lattice vibrations in orthorhombic TaS_3 are investigated by polarized Raman scattering. Below the phase transition temperature of 218 K, satellite peaks become strong on the lower-energy slopes of the broad peaks which are dominant at room temperature. The decrease of the dominant peak below T_c is attributed to the decrease of the scattering probability from the intraband process in the chain with a large CDW gap, with the assumption that the interchain interaction is weak and the satellite peaks are due to the same normal modes of 24 chains in the unit cell.