The growth of single crystals of some organic compounds by the Czochralski technique and the assessment of their perfection

Abstract The application of the Czochralski technique to the growth of crystals of some organic materials is described. It is found that the low melting points, thermal conductivities and melt-surface tensions of these compounds are not a barrier to the use of this method of crystal growth. Crystals of dimensions up to 10 cm 3 can be pulled in periods of 1–2 days. The analysis of the perfection of the products by X-ray topography is described and indicates that the crystals contain substantial volumes (cm 3 ) which are essentially dislocation-free. This represents a considerable improvement on the crystals produced by the more commonly used Bridgman technique and compares favourably with the perfection achievable by growth from solution in much longer periods.