Untersuchungen der optischen Eigenschaften farbiger Kaliumchloratkristalle

On crystallizing KClO3 from a solution, there are formed monocline crystal plates which strike by their bright coloured reflectibility. Previous publications by other authors explained this appearence to be an interference phenomenon, caused by strata structure of the plates consisting of twin lamellae with alternating refractive index. The present authors have investigated thoroughly the optical properties of such crystals. The accordance of the measured values with a simple lattice theory is satisfactorily up to angles of incidence of 45°. For still greater angles the double refraction of KClO3 must be accounted for. In a paper by G. Becker to be published soon it will be shown that even the phenomena in polarized light can be explained by a theory of such type. Further discussion shows that discrepancies caused by lattice disturbances are of minor importance. A further publication will deal with the question of the mechanism of formation of these regularly structured strata containing up to 1000 such reflecting layers.