On the optical properties of some layer compounds

The paper deals with the optical properties of single crystals near the fundamental absorption edge of the following layer compounds: Sn Sx Se2−x (where 0 ⩽ x ⩽ 2), ZrS2, ZrSe2, TiS2 and CdI2. The dispersion curves were determined from the transmitted interference fringes in the range between 0.5 and 3.5 μm. Energy gaps were found to be due to phonon assisted indirect transitions. Birefringence data are also given for a number of crystals in the visible region.