Optical Properties of Cadmium Single Crystals

The optical properties of cadmium single crystals and of a cadmium film deposited by vacuum evaporation were measured in the energy range from 0.5 to 5.5 eV in dependence on temperature, crystal orientation, and the pressure in the vacuum chamber. The results prove that oxide layers become effective only at higher energies. The influence of adsorbed impurity films, which arise on the sample surfaces at low temperatures, is negligible at a pressure of p = 10 −9 Torr, while the results obtained at higher pressures are falsified in the whole energy region investigated. The results obtained at a pressure of p = 10 −9 Torr agree with theoretical calculations of the optical absorption.