TiC(110)表面第一性原理研究(英文)

利用基于密度泛函理论的第一性原理平面波赝势法计算TiC(110)表面的结构和电子特性。对于该表面结构弛豫和表面能的计算结果表明,7层原子构型能够显示TiC的内部体相特征,弛豫后结构的变化仅发生在顶部3层,证明弛豫只影响构型的顶部3层。同时,从构型的(100)平面上的电荷密度分布中可以看到强烈的Ti—C共价键。弛豫后,由于电荷在真空层中的消耗和第一、第二层原子层之间的积累,第一、第二层原子间距减小,Ti—C化学键相应地增强。计算得到的TiC(110)表面的表面能为3.53J/m2。

First-principles study of TiC(110) surface

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.