The effect of low-pressure oxygen, present during condensation, on the structure of tin films

Abstract

Electron microscopy and electron diffraction are used to investigate the structure of tin films condensed on glass substrates at room temperature in ultra-high vacuum at 10⁻⁸ torr and in oxygen at 10⁻⁵ torr. The (100) orientation, independent of thickness, of films formed in high vacuum represents the state of lowest surface energy attained as the result of high surface mobility of the tin atoms. The presence of oxygen evidently reduces this mobility, leading to continuous films only a few hundred angstroms thick with other orientations. These latter orientations alter as the films grow thicker and appear to originate from the development of the corresponding orystallographic face on the growing crystals.