First-principles study of TiC(110) surface
(1. School of Mechanical and Electronic Engineering, Shandong University at Weihai, Weihai 264209, China;
2. Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials, Ministry of Education,
Shandong University, Ji’nan 250061, China)
2. Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials, Ministry of Education,
Shandong University, Ji’nan 250061, China)
Abstract: The structural and electronic properties of TiC(110) surfaces are calculated using the first-principles total-energy plane-wave pseudopotential method based on density functional theory. The calculated results of structural relaxation and surface energy for TiC(110) slab indicate that slab with 7 layers shows bulk-like characteristic interiors, and the changes of slab occur on the outmost three layers, which shows that the relaxation only influences the top three layers. Meanwhile, the strong Ti—C covalent bonding can be found in the distribution of charge density on the (100) plane. The interlayer Ti—C chemical bonds are reinforced and the outermost interlayer distance is reduced as a result of the charge depletion in the vacuum and the charge accumulations in the interlayer region between the first and second layers. The surface energy of TiC(110) is calculated to be 3.53 J/m2.
Key words: first-principles; TiC(110) surface; charge distribution; structural relaxation