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Proceedings Paper

Modeling of phase transitions in aluminum-gallium oxide alloys (Conference Presentation)
Author(s): Catalin S. Badescu

Paper Abstract

The epitaxial growth of beta-aluminum-gallium oxide alloys on beta-gallium oxide substrates is limited by the difference in lattice constants and lattice symmetries of beta-gallium oxide (monoclinic) and aluminum oxide (corundum). The monoclinic and corundum phases of the alloys have been compared mostly on the grounds of their total energies at zero Kelvin, considering that the vibrational entropy contribution is relatively small. Here we show that the lattice mismatch-induced strain can lead to zone edge softening, providing a path for phase transitions in epitaxial growth of aluminum-gallium oxide alloys. This mechanism depends on both the alloy concentration ratio and on the direction of growth. Detailed insights are obtained from first-principles calculations of total energies and vibrational spectra throughout the Brillouin zone.

Paper Details

Date Published: 8 March 2019
Proc. SPIE 10919, Oxide-based Materials and Devices X, 1091908 (8 March 2019); doi: 10.1117/12.2514838
Show Author Affiliations
Catalin S. Badescu, Air Force Research Lab. (United States)

Published in SPIE Proceedings Vol. 10919:
Oxide-based Materials and Devices X
David J. Rogers; David C. Look; Ferechteh H. Teherani, Editor(s)

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