中文摘要：

采用平面波超软赝势方法计算了锐钛矿型TiO2（101）面存在本征空位和间隙点缺陷的几何结构以及缺陷形成能.首先分析了点缺陷对表面结构的影响,发现不同类型缺陷导致缺陷周围原子有不同的位移趋势：O空位的产生导致空位周围的Ti原子向空位外移动,Ti1和Ti2空位的产生均使O1自发地与周围的O原子团聚,Oi原子易被周围的氧原子吸附而成键,而Tii2缺陷几乎对晶格结构没有产生影响.对TiO2（101）面上可能出现的几种点缺陷的形成能进行了计算,结果表明：在还原性气氛下,虽然Tii2和VO1缺陷均容易出现,但Tii2缺陷的形成能比VO1缺陷更低;而在氧化性气氛下,表面的Oi和VTi1缺陷较容易出现.最后,为了比较各种缺陷结构的稳定性,还计算了几种典型表面缺陷的形成焓.

英文摘要：

First-principles plane-wave pseudopotential calculations were performed to study the energetics and the geometical structures of intrinsic vacancies and interstitials on the anatase TiO2 （101） crystal surface. Firstly, we analyzed the effects of point defects on the geometrical structures. For the O vacancy, all the nearest-neighbor Ti atoms move away from the vacancy toward the other O neighborhood. As Ti1 or Ti2 is missing here, O1 atom spontaneously and strongly binds with nearest-neighbor O on the lattice site to form an O2 molecule. The results also show that interstitial Tii2 affects little host lattice and the interstitial Oi would spontaneously bind to lattice oxygen. By investigating the calculated defect formation energies, we found that under the O-rich condition, the VTiI and O1 formation are favorable, however, under the Ti-rich condition, although the point defects of Tii2 and Vol easily appear, the formation energy of the Tii2 is lower than that of the Vol - Finally, to determine the relative stability of the point defects, the formation enthalpies of several point defects were considered.