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arXiv 1201.3853cond-mat.mtrl-sci
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基于第一性原理计算的BaTiO3电导率模型

Modeling the electrical conductivity in BaTiO3 on the basis of first-principles calculations

Paul Erhart, Karsten Albe

摘要:

基于从密度泛函理论内的第一性原理计算获得的数据,计算了原型钙钛矿$\Ba\TiØ_3$的电导率对氧分压的依赖性。通过自洽确定的电子化学势的平衡点缺陷浓度。这允许导出给定温度和化学环境的载流子浓度,并最终导出电导率。如果假设$10^{17}\,\cm^{-3}$为意外受主掺杂水平,则计算结果与实验数据非常吻合。结果表明,双电荷氧空位是负责高温$n$型导电在贫氧条件下。高温$p$型导电观察到在大的氧气压力是由于钡空位和钛-氧双空位在Ti和Ba丰富的条件下,分别。最后,讨论了本方法与点缺陷热力学的质量作用定律方法之间的联系。

英文摘要:

The dependence of the electrical conductivity on the oxygen partial pressure is calculated for the prototypical perovskite $\Ba\TiØ_3$ based on data obtained from first-principles calculations within density functional theory. The equilibrium point defect concentrations are obtained via a self-consistent determination of the electron chemical potential. This allows to derive charge carrier concentrations for a given temperature and chemical environment and eventually the electrial conductivity. The calculations are in excellent agreement with experimental data if an accidental acceptor dopant level of $10^{17}\,\cm^{-3}$ is assumed. It is shown that doubly charged oxygen vacancies are accountable for the high-temperature $n$-type conduction under oxygen-poor conditions. The high-temperature $p$-type conduction observed at large oxygen pressures is due to barium vacancies and titanium-oxygen di-vacancies under Ti and Ba-rich conditions, respectively. Finally, the connection between the present approach and the mass-action law approach to point defect thermodynamics is discussed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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