Far-Infrared Reflection Spectra of CsCl Single Crystals

Abstract

Far-infrared reflectivity measurements have been made at room temperature for CsCl single crystals obtained by the melt-growth under high pressure. The reflection spectra have been analyzed using Kramers-Kronig relation and the classical two oscillator model, and optical constants (n, k) are calculated. The sideband structure has been clearly observed near 140cm⁻¹, which is discussed by considering the relaxation of the resonant TO phonon anharmonically coupled with two other phonons.