A Computer Simulation Investigation of Brownmillerite-Structured Ba2In2O5
A Computer Simulation Investigation of Brownmillerite-Structured Ba2In2O5
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褐针石结构Ba2In2O5的计算机模拟研究
DOI：
10.1006/jssc.1996.7187
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发表时间：
1997
影响因子：
5.4
通讯作者：
R. Brook
中科院分区：
文献类型：
--
作者：
C. Fisher;M. Islam;R. Brook
摘要采用原子模拟技术研究了Ba2In2O5的晶体结构和缺陷能量学。一个原子间的潜力模型，再现斜方晶系brownmillerite结构，交替层的氧八面体和四面体。缺陷计算表明，能量最有利的本征缺陷是弗伦克尔型，在O（1）位上的氧空位和氧离子在四面体层的间隙位置。计算的电子缺陷的形成能表明，Ba 2 In 2 O 5将氧化形成的正空穴，有助于实验观察到的电子导电性。最后，考虑结构中可能的氧离子迁移路径，发现在[001]方向上氧八面体的赤道位置之间的迁移能垒最低。
Abstract Atomistic simulation techniques have been used to investigate the crystal structure and defect energetics of Ba 2 In 2 O 5 . An interatomic potential model was developed that reproduces the orthorhombic brownmillerite structure, with alternating layers of oxygen octahedra and tetrahedra. Defect calculations show that the most energetically favorable intrinsic defects are of the Frenkel type, with an oxygen vacancy on the O(1) site and an oxygen ion in an interstitial position in the tetrahedral layer. Calculated formation energies of electronic defects suggest that Ba 2 In 2 O 5 will oxidize with the formation of positive holes, contributing to the electronic conductivity that is observed experimentally. Finally, consideration of possible oxygen ion migration pathways in the structure found that energy barriers to migrationare lowest between equatorial sites of oxygen octahedra in the [001] direction.