The growth of hillocks and voids in gold single crystals by electrotransport

Abstract

Surface changes resulting from electrotransport were observed on gold single crystal foils with surface orientations of {100}, {110} and {111} as a function of location on the specimen, temperature and time using the scanning electron microscope. As a result of electrotransport, hillocks and voids occur bounded by low index crystallographic planes. The direction of material flow is from cathode to anode. The hillocks are observed on the surface of the anode region of the specimen and the voids on the surface and the interior of the cathode region. Both hillocks and voids are arranged along 〈110〉 directions. The initial linear growth rate of the hillocks falls to zero after prolonged annealing. Quantitative analysis of the results shows that the driving forces of electrotransport are responsible for the observed volume change. In the initial stages the material current can be described by the bulk self diffusion of gold.