Browsing by Subject "Surface phenomena"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access First-principles study of superlow friction between hydrogenated diamond surfaces(ASME, 2005) Çıracı, Salim; Dağ, SefaAttractive interaction between two clean diamond(001) slabs turns repulsive upon the hydrogenation of surfaces. Even under high loading forces, this repulsive interaction prevents the sliding surfaces from being closer to each other. As a result, calculated lateral force variation generated during sliding has small magnitude under high constant loading forces. Superlow friction observed earlier between diamond like carbon coated surfaces can be understood by the steady repulsive interaction between sliding surfaces, as well as strong and stiff carbon-carbon and carbon-hydrogen bonds which do not favor energy dissipation. In ambient conditions, the steady repulsive interaction is, however, destroyed by oxygenation of hydrogenated surface.Item Open Access Model study of a surfactant on the GaAs(100) surface(Elsevier, 2002-11-01) Consorte, C. D.; Fong, C. Y.; Watson, M. D.; Yang, L. H.; Çıracı, SalimBased on the facts that: (a) the transverse acoustic vibrational branch frequency is softened at the Brillouin zone boundaries of crystalline GaAs; (b) at the surface, the Ga-As bond is stronger than Ga-Te bond; and (c) the requirement that the final bond orientation of the Te surfactant should be rotated by 90degrees with respect to its initial orientation, we carried out a model study of an exchange process in epitaxial growth of GaAs (100). Even with very restrictive conditions imposed on the atomic movements, this study explains why Te is an effective surfactant for this type of growth. (C) 2002 Elsevier Science B.V. All rights reserved.