当前位置:
X-MOL 学术
›
Low Temp. Phys.
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
First principles hybrid Hartree-Fock-DFT calculations of bulk and (001) surfaceFcenters in oxide perovskites and alkaline-earth fluorides
Low Temperature Physics ( IF 0.8 ) Pub Date : 2020-12-22 , DOI: 10.1063/10.0002475 R. Eglitis 1 , A. I. Popov 1 , J. Purans 1 , Ran Jia 1, 2
Low Temperature Physics ( IF 0.8 ) Pub Date : 2020-12-22 , DOI: 10.1063/10.0002475 R. Eglitis 1 , A. I. Popov 1 , J. Purans 1 , Ran Jia 1, 2
Affiliation
We report the results of ab initio calculations and analysis of systematic trends for the F centers in the bulk and on the (001) surface in oxide perovskites, such as BaTiO3, SrTiO3, SrZrO3, and PbZrO3, with a corresponding comparison of the F centers in perovskites with those in alkaline earth metal fluorides (CaF2, BaF2, and SrF2). It was found that in perovskites in both bulk F centers and those on their (001) surfaces, two nearest to the vacancy Ti or Zr atoms repel each other, while the next nearest O atoms relax towards the oxygen vacancy. It was also found that the obtained relaxations of atoms in the nearest neighborhood around the F center in ABO3 perovskites are generally larger than in alkaline earth metal fluorides. The bulk and (001)-terminated surface F center ground states in BaTiO3, SrTiO3, and SrZrO3 perovskites are located 0.23, 0.69, 1.12 eV, and 0.07, 0.25, 0.93 eV, respectively, below the conduction band bottom, indicating that the F center is a shallow donor. The vacancies in BaTiO3, SrZrO3, and PbZrO3 are occupied with 1.103e, 1.25e, and 0.68e, respectively, whereas slightly smaller charges, only 1.052e, 1.10e, and 0.3e are localized inside the F center on the perovskite (001) surface. In contrast to the partly covalent ABO3 perovskites, charge is well localized (around 80%) inside the ionic CaF2, BaF2, and SrF2 fluorine vacancy.
中文翻译:
氧化物钙钛矿和碱土氟化物中体积和(001)表面中心的第一原理混合Hartree-Fock-DFT计算
我们报告的结果从头计算和的对系统的趋势分析˚F在本体和在氧化物钙钛矿,如钛酸钡(001)表面上的中心3,的SrTiO 3,SrZrO 3,和的PbZrO 3,与对应的比较钙钛矿中F的中心与碱土金属氟化物(CaF 2,BaF 2和SrF 2)中的F中心相同。发现在钙钛矿中,散装的F中心和其(001)表面上的原子,两个最接近空位的Ti或Zr原子互相排斥,而下一个最接近的O原子朝着氧空位弛豫。还发现,在ABO 3钙钛矿中,F中心附近最近的原子所获得的弛豫通常大于碱土金属氟化物中的弛豫。BaTiO 3,SrTiO 3和SrZrO 3钙钛矿中的本体和(001)端接的表面F中心基态分别位于导带底部下方0.23、0.69、1.12 eV和0.07、0.25、0.93 eV。该˚F中心是一个浅施主。BaTiO 3中的空位,SrZrO 3和PbZrO 3分别被1.103 e,1.25e和0.68 e占据,而稍小的电荷,仅1.052 e,1.10 e和0.3 e位于钙钛矿(001)表面的F中心。 。与部分共价的ABO 3钙钛矿相反,电荷在离子CaF 2,BaF 2和SrF 2的氟空位内定位良好(约80%)。
更新日期:2020-12-30
中文翻译:
氧化物钙钛矿和碱土氟化物中体积和(001)表面中心的第一原理混合Hartree-Fock-DFT计算
我们报告的结果从头计算和的对系统的趋势分析˚F在本体和在氧化物钙钛矿,如钛酸钡(001)表面上的中心3,的SrTiO 3,SrZrO 3,和的PbZrO 3,与对应的比较钙钛矿中F的中心与碱土金属氟化物(CaF 2,BaF 2和SrF 2)中的F中心相同。发现在钙钛矿中,散装的F中心和其(001)表面上的原子,两个最接近空位的Ti或Zr原子互相排斥,而下一个最接近的O原子朝着氧空位弛豫。还发现,在ABO 3钙钛矿中,F中心附近最近的原子所获得的弛豫通常大于碱土金属氟化物中的弛豫。BaTiO 3,SrTiO 3和SrZrO 3钙钛矿中的本体和(001)端接的表面F中心基态分别位于导带底部下方0.23、0.69、1.12 eV和0.07、0.25、0.93 eV。该˚F中心是一个浅施主。BaTiO 3中的空位,SrZrO 3和PbZrO 3分别被1.103 e,1.25e和0.68 e占据,而稍小的电荷,仅1.052 e,1.10 e和0.3 e位于钙钛矿(001)表面的F中心。 。与部分共价的ABO 3钙钛矿相反,电荷在离子CaF 2,BaF 2和SrF 2的氟空位内定位良好(约80%)。