Solute striae in pulled crystals of zinc tungstate

Abstract

Three principal types of solute striae are found in rhodium-doped zinc tungstate crystals grown by the Czochralski method. These are (i) striae, visible to the eye, associated with impressed melt temperature fluctuations, (ii) finer striae which may be correlated with regular oscillations of melt temperature caused by instabilities in the melt and (iii) striae with a spacing given by the ratio of growth rate to rotation rate. A theory is proposed to account for the spacing and magnitude of the larger types of striae.