Impurities and the Evaporation Morphology of Zinc Single Crystals

Abstract

<p> In this thesis the results of optical and scanning electron microscopic investigations of the evaporation morphology of zinc single crystals are presented. Dislocation etch pits developed on (0001) zinc cleavage surfaces. A mechanism is proposed to account for enhanced evaporation at decorated dislocations. The observation of macroledges on pit faces is reported and attributed to impurity-induced bunching of monatomic ledges, the impurities having out-diffused from the bulk. A proposed model for evaporation of faceted surfaces is used to interpret the ledge morphology which developed when samples were evaporated in an oxygen environment. Finally, a correlation between the effects of bulk impurities and gaseous impurities on ledge morphology is demonstrated.</p>