Electron Microscopic Observation of Oxide Crystals Grown on Thin Film of α-Brass at Elevated Temperature

Publisher Website
Google Scholar
Abstract
Electrolytically-thinned α-brass foils containing dislocations, stacking faults and grain boundaries are heated at the temperatures between 200°C and 600°C in the air pressures between 1×10-4 Torr and 760 Torr in order to investigate the relation between the crystal imperfections and the oxide crystals formed on the surface. It is observed in the electron microscopic images that the particles of ZnO, Cu2O and CuO are formed on the surface of the specimen corresponding to heating conditions without any special relation to the imperfections in α-brass. It is also observed that hexagonal or irregular shaped thin regions are formed in the specimen by the evaporation of α-brass in the air pressures below 4 Torr at above 400°C. When the specimens of a few microns in thickness are heated, the needle-shaped zinc oxide crystals grow on the surface of α-brass with the axis of [100]. Sometimes drop-like particles are formed on the walls and at the tips of the needles. The evaporation mechanism of α-brass during oxidation and the role of drops to the crystal growth of needles are discussed.