【摘要】 采用基于密度泛函理论的局域密度近似平面波超软赝势法 ,在周期边界条件下的k空间中 ,对最外表面终止层为单层Al的α Al2 O3( 0 0 0 1 )表面结构进行了弛豫与电子结构计算研究 .通过分析表面弛豫前后表面电子密度、态密度变化 ,表明表面能级分裂主要来自于O的2 p轨道电子态变化 ,α Al2 O3( 0 0 0 1 )表面明显地表现出O的表面态 .通过电子局域函数图 ,进一步分析了表面成键与表面电子分布特性 .更多还原

【Abstract】 The structure of the α-Al_ 2O_ 3(0001) super-cell (2×2) surface with single Al-terminated are studied using Ab initio quantum-mechanical calculations based on density-functional theory and pseudopotential method. The calculations employ slab geometry and periodic boundary conditions,with the occupied orbitals expanded in plane waves. Through an analysis of the difference of the density of state and electron charge density between the unrelaxed and relaxed surface,we found that the α-Al_ 2O_ 3(0001) crystal surface clearly appears the O-surface state which mainly comes from the O-2p states. The electron density and bonding characteristics of the surface are also shown by electron localization function(ELF).更多还原