First-principles prediction of disordering tendencies in pyrochlore oxides
First-principles prediction of disordering tendencies in pyrochlore oxides
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DOI：
10.1103/physrevb.79.104203
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发表时间：
2009-03-01
影响因子：
3.7
通讯作者：
Uberuaga, B. P.
中科院分区：
文献类型：
--
作者：
Jiang, Chao;Stanek, C. R.;Uberuaga, B. P.
采用第一性原理计算方法，系统地预测了锆酸盐（A（2）Zr（2）O（7））、锆酸盐（A（2）Hf（2）O（7））、钛酸盐（A（2）Ti（2）O（7））和锡酸盐（A（2）Sn（2）O（7））系列高温超导体的有序-无序能量学.无序的缺陷萤石结构建模使用88个原子的两个子晶格的特殊准随机结构（SQS），密切再现最相关的近邻intrasublattice和intersublattice对相关函数的随机混合物。从我们的SQS计算估计这些高温超导体的有序-无序转变温度与现有的实验显示出总体良好的协议。我们证实了以前的研究表明，在pyrophileres键合不是纯粹的离子，因此电子效应也发挥了作用，在确定其无序的趋势。我们的研究结果对许多应用，包括核废料形式和快离子导体有重要的影响。
Using first-principles calculations, we systematically predict the order-disorder energetics of series of zirconate (A(2)Zr(2)O(7)), hafnate (A(2)Hf(2)O(7)), titanate (A(2)Ti(2)O(7)), and stannate (A(2)Sn(2)O(7)) pyrochlores. The disordered defect-fluorite structure is modeled using an 88-atom two-sublattice special quasirandom structure (SQS) that closely reproduces the most relevant near-neighbor intrasublattice and intersublattice pair-correlation functions of the random mixture. The order-disorder transition temperatures of these pyrochlores estimated from our SQS calculations show overall good agreement with existing experiments. We confirm previous studies suggesting that the bonding in pyrochlores is not purely ionic and thus electronic effects also play a role in determining their disordering tendencies. Our results have important consequences for numerous applications, including nuclear waste forms and fast ion conductors.