原子与分子物理学报2017，Vol.34Issue(4)：689-695,7.DOI:10.3969/j.issn.1000-0364.2017.04.016
高压下铌铁矿相TiO2直接相变的第一性原理研究
First-principles study of direct phase transition of columbite TiO2 under high pressure
摘要
Abstract
The GGA+U method based on the first principles is used to calculate the rutile, columbite, fluorite, pyrite, and P42/nmc TiO2 phases.Firstly, the crystal structure of these phases are optimized and the related parameters are obtained.The enthalpy curves are analyzed.It is found that the columbite can directly change to a tetragonal P42/nmc structure under 50.1 GPa pressure.Secondly, the energy band structures of the P42/nmc TiO2 are calculated and discussed by GGA+U and HSE06 methods.The third-order Birch-Murnaghan equation of state and the XRD spectra are fitted and analyzed.Finally, it is thought that fluorite and P42/nmc may be coexisting phases, which is in accordance with the experimental results of the pressure range, bulk modulus and XRD spectra of cubic TiO2.关键词
第一性原理/TiO2/相变/四方P42/nmcTiO2Key words
The first principles/TiO2/Phase transition/Tetragonal P42/nmc TiO2分类
数理科学引用本文复制引用
董海宽,齐义辉,高亚军,修晓明,史力斌..高压下铌铁矿相TiO2直接相变的第一性原理研究[J].原子与分子物理学报,2017,34(4):689-695,7.基金项目
国家自然科学基金(11271055,11674037) （11271055,11674037）
辽宁省教育厅一般项目(20140445) （20140445）
