کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5426082 | 1395874 | 2007 | 7 صفحه PDF | دانلود رایگان |
A simple, rigid pair-potential model is applied to investigate the dynamics of the (0 0 0 1) α-Al2O3 and α-Cr2O3 surfaces using the molecular dynamics technique. The simulations employ a two-stage equilibration process: in the first stage the simulation-cell size is determined via the constant-stress ensemble, and in the second stage the equilibration of the size-corrected simulation cell is continued in the canonical ensemble. The thermal expansion coefficients of bulk alumina and chromia are evaluated as a function of temperature. Furthermore, the surface relaxation and mean-square displacement of the atoms versus depth into the slab are calculated, and their behaviour in the surface region analysed in detail. The calculations show that even moderate temperatures (â¼400 °C) give rise to displacements of the atoms at the surface which are similar to the lattice mismatch between α-alumina and chromia. This will help in the initial nucleation stage during thin film growth, and thus facilitate the deposition of α-Al2O3 on (0 0 0 1) α-Cr2O3 templates.
Journal: Surface Science - Volume 601, Issue 5, 1 March 2007, Pages 1358-1364