Long-wavelength phonons inTlSbS2. II. Raman-active modes under hydrostatic pressure

We report the evolution of the first-order Raman modes of the layered semiconductor ${\mathrm{TlSbS}}_2$ with hydrostatic pressure applied up to 10 kbar. All the modes experience a blue shift, except the mode at 286 ${\mathrm{cm}}^{\mathrm{-}1}$, whose insensitivity to pressure shows it to be governed by stretching of Sb-S diatomic chains in the layer. An axially symmetric short-range potential between nearest neighbors has been constructed to account for the full Raman spectrum.