Effect of temperature and deposition rate on the structure of vacuum alumina condensates

Vacuum alumina condensates are prepared by electron-beam (at different deposition rates) and pulsed-laser vapor deposition onto polycrystalline molybdenum substrates heated over a wide temperature range. X-ray and electron diffraction and scanning and transmission electron microscopy are used to examine the phase composition, microstructure, and surface morphology of the vacuum condensates. The dependence of the condensate structure on the temperature and deposition rate is established. The experimental data are explained by vapor → crystal or vapor → liquid → crystal vacuum condensation mechanisms depending on the evaporation method. The results permit choosing optimal parameters for the deposition of condensates with needed properties.