作　　者： ; ; ;

机构地区： 华南师范大学物理与电信工程学院

出　　处： 《华南师范大学学报（自然科学版）》 2009年第4期52-56,共5页

摘　　要： 基于第一性原理中的密度泛函理论,采用CASTEP程序包,计算分析了锐钛矿型TiO2的能带结构、电子态密度和弹性常数等性能参数.结果表明,锐钛矿型TiO2属间接带隙半导,最小能隙为2.2eV.Ti和O之间存在明显的电子转移现象,电子分布具有强烈的定域性,但由于存在杂化现象,Ti-O键还表现出部分共价键特征.在四方晶系中,这种离子键和共价键混合的网络状复合键结构使材料表现出大的体积弹性模量204.44GPa,由于在TiO2晶体结构中,滑移系统较少,材料断裂时突凸显脆性,韧性差,剪切模量相对较小为64.71GPa. Based on density functional theory （DFT） of the first principle, the electronic structures, total density of states （DOS） and elastic constants of anatase - TiO2 are investigated by Cambridge serial total energy package （CASTEP） program. The orbits of Ti and O are also discussed. It is found that the TiO2 is the semiconductor with the indirect band gap about 2. 2 eV. The results indicate that there are obvious electron transition between O and Ti atomic, and the electron is visibly localized. The partial covalent bond exists due to the hybrid orbital. In tetragonal crystal system, TiO2 is characterized with the high bulk modulus about 204. 44 GPa because of the network structure of complex bonds. The system is lack of gliding planes, materials are easily broken by brittle fracture, and the shear modulus is relatively low only about 64. 71 GPa.

关 键 词： 锐钛矿 第一性原理

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]