Infra-red studies of TiSe2: IR phonons and free carriers

Abstract
The infra-red reflectivity of TiSe2 has been studied as a function of temperature in order to gain information relevant to the (2a × 2a × 2c) phase transition at 202 K. This paper emphasizes the properties of the IR-active phonons (E ⊥ c axis polarization) and the free carriers. The behaviour found supports a model in which the phase transition is driven by lattice phonons.