Optical Constants and Polarization-Dependent Reflection Spectra of CdCl₂ and CdBr₂ Single Crystals

Abstract

Optical constants of CdCl₂ and CdBr₂ at room and liquid helium temperatures have been determined in the region 4–11 eV for ordinary ray from reflection spectra of the cleaved surfaces. The structures near the optical gap in the optical conductivity spectra are interpreted in terms of the optical transitions occuring at the Γ point in the Brillouin zone. The interpretation has been confirmed by the measurements of the polarization-dependent reflection spectra of the polished surfaces parallel to the c axis. The structures in the deep interband energy region are related to the transitions at the Z point on the basis of their polarization dependence.