Low‐energy Sr 2 MSbO5.5 (M = Ca and Sr) structures show significant distortions near oxygen vacancies
Low‐energy Sr 2 MSbO5.5 (M = Ca and Sr) structures show significant distortions near oxygen vacancies
复制标题
低能 Sr 2 MSbO5.5（M = Ca 和 Sr）结构在氧空位附近表现出明显的扭曲
DOI：
10.1002/qua.26356
复制
发表时间：
2020
影响因子：
2.2
通讯作者：
King, Graham
中科院分区：
文献类型：
--
作者：
Patel, Megha;Zhong, Jiayun;Gomez‐Haibach, Konrad S.;Gomez, Maria A.;King, Graham
受中子对分布函数分析研究中发现的空位附近的显著局部扭曲的启发（G。King等，Inorg.Chem.2012，51，13060）的Sr2MSbO5.5（M = Ca和Sr），该计算研究使用具有Perdew-Burke-Ernzerhof（PBE）泛函的密度泛函理论（DFT）发现了具有这些和相关畸变的最小能量结构，如在维也纳Ab Initio Simulations Package（VASP）（G. Kresse和J. Furthmüller，Phys. Rev. B，1996，54，11169; G. Kresse和J. Hafner，Phys. Rev. B，1993，47，558; G. Kresse和J. Furthmüller，计算。Mater.科学，1996，6，15）。所有结构均采用共轭梯度法进行优化。这两个系统的全局最小值都具有三角双锥SbO 5结构和与M-中心多面体共享的边缘。然而，虽然钙离子占据全部和部分八面体，较大的锶离子更常见于全部和部分五角双锥。分子动力学与速度重新标度atK揭示运动的氧空位通过多面体旋转。这项工作强调了在模拟缺氧双钙钛矿中的氧空位传导时，需要考虑小离子周围的正方形金字塔到三角形双金字塔重排和旋转多面体运动。
Inspired by significant local distortions found near vacancies in a neutron pair distribution function analysis study (G. King et al.,Inorg. Chem.2012, 51, 13060) of Sr2MSbO5.5(M = Ca and Sr), this computational study finds minimum‐energy structures with these and related distortions using density functional theory (DFT) with the Perdew‐Burke‐Ernzerhof (PBE) functional as implemented in the Vienna Ab Initio Simulations Package (VASP) (G. Kresse and J. Furthmüller,Phys. Rev. B, 1996, 54, 11169; G. Kresse and J. Hafner,Phys. Rev. B, 1993, 47, 558; G. Kresse and J. Furthmüller,Comput. Mater. Sci., 1996, 6, 15). All structures were optimized using the conjugate gradient method. The global minima found for both systems featured trigonal bipyramid SbO5structures and edge sharing with M‐centered polyhedra. However, while calcium ions occupied full and partial octahedra, the larger strontium ions were more commonly found in full and partial pentagonal bipyramids. Molecular dynamics with velocity rescaling atK revealed movements of the oxygen vacancy via polyhedral rotations. This work highlights the need to consider both square pyramid to trigonal bipyramid rearrangements around small ions and rotational polyhedral movements in simulating oxygen vacancy conduction in oxygen‐deficient double perovskites.