Structure and energetics of stoichiometric TiO2 anatase surfaces -: art. no. 155409
Structure and energetics of stoichiometric TiO2 anatase surfaces -: art. no. 155409
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DOI：
10.1103/physrevb.63.155409
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发表时间：
2001-04-15
影响因子：
3.7
通讯作者：
Selloni, A
中科院分区：
文献类型：
--
作者：
Lazzeri, M;Vittadini, A;Selloni, A
我们提出了一个从头算密度泛函研究的结构和能量的几个化学计量的1 × 1低指数表面的金红石，一个TiO 2多晶型物类似于9%的密度和类似于1.2千卡/摩尔不稳定的金红石。虽然我们的计算不再现实验观察到的两个阶段的相对顺序，计算的两个多晶型体的整体结构和弹性性质与实验非常一致，这表明表面弛豫正确描述。正如预期的那样，表面能的x-ray似乎是有关的存在下配位的Ti原子：表面与四重配位的Ti原子有一个更大的能量比那些与五重配位的Ti。此外，我们发现，平均表面能的二氧化钛的金红石宏观晶体是小于金红石。最后，分析了不同表面原子的弛豫模式。
We present an ab initio density-functional investigation of the structure and energetics of several stoichiometric 1 X 1 low-index surfaces of anatase, a TiO2 polymorph similar to9% less dense and similar to1.2 kcal/mol less stable than rutile. Although our calculations do not reproduce the relative ordering of the two phases that is observed experimentally, the calculated bulk structural and elastic properties of both polymorphs are in excellent agreement with the experiment, suggesting that surface relaxations are correctly described as well. As expected, the surface energies of anatase appear to be related to the presence of undercoordinated Ti atoms: the surfaces with fourfold-coordinated Ti atoms have a larger energy than those with fivefold-coordinated Ti. Furthermore, we find that the average surface energy of a TiO2 anatase macroscopic crystal is smaller than that of rutile. Finally, patterns in the relaxation of the surface atoms which are com;non to different surfaces are analyzed.