Structural and thermodynamic aspects of the evolution of supersmooth surface of oxide crystals
| Autor: | Abil Asvarov, Alfred P. Chernyshev, A. E. Muslimov, V. M. Kanevsky, A. V. Butashin |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Surface diffusion
Materials science Incongruent melting Annealing (metallurgy) Diffusion Oxide General Physics and Astronomy 02 engineering and technology Surfaces and Interfaces General Chemistry Crystal structure Atmospheric temperature range 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Crystal chemistry.chemical_compound chemistry Chemical physics 0210 nano-technology |
| Zdroj: | Applied Surface Science. 553:149541 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2021.149541 |
| Popis: | Evolution of the α-Al2O3, La3Ga5SiO14, and LaMgAl11O19 single crystals supersmooth surfaces at annealing in air was investigated using thermodynamic calculations. In particular the characteristic temperatures and annealing ranges were calculated when the surface melting phenomena took place or atomically smooth steps were formed and moved due to the surface diffusion processes. Later conclusion was confirmed in the surface probe microscopy experiments with regard to the crystal structure data of α-Al2O3, La3Ga5SiO14, and LaMgAl11O19, specifically the surface diffusion processes dominated at comparably low annealing temperatures (less than surface melting temperature T sm ). In this temperature range the crystal structure near the surface was rather stable, that is why one could assume the electrically neutral clusters of Al2O3, LaMgAl11O19 и La3Ga5SiO14 involved in the surface diffusion processes instead of single atoms. A further increase in annealing temperature to T sm resulted in the La3Ga5SiO14 crystal surface thermodestruction due to probably incongruent melting of La3Ga5SiO14 compound and related friability of its structure if to compare it with Al2O3 and LaMgAl11O19 structures with the layers of close-packed oxygen atoms. |
| Databáze: | OpenAIRE |
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