FURTHER OBSERVATIONS ON THE MACROMOSAIC STRUCTURE OF TIN SINGLE CRYSTALS

Abstract

Further studies are reported on the bands, or striations, into which single crystals of high purity tin, grown by a modified Bridgman method, are partitioned. This striation structure is shown to exist throughout the whole volume of the crystal. The direction in which the boundaries of the striations form relative to the specimen axis is shown to be a compromise between thermal and crystallographic conditions, in which the orientation of the (110) planes is the determining factor. When new striations are formed, they are found to have an incubation period which is longer the slower the rate of growth of the crystal. A qualitative mechanism is developed, based on the formation of dislocations into transition surfaces constituting the striation boundaries, which is consistent with all the experimental observations.