Point defects and cation tracer diffusion in (TixFe1−x)3−δO4 1. Non-stoichiometry and point defects
Point defects and cation tracer diffusion in (TixFe1−x)3−δO4 1. Non-stoichiometry and point defects
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(TixFe1−x)3−δO4 中的点缺陷和阳离子示踪剂扩散 1. 非化学计量和点缺陷
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
R. Dieckmann
中科院分区：
文献类型：
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作者：
S. Aggarwal;R. Dieckmann
摘要 在 x=0.1、0.2 和 0.25 的 (TixFe1−x)3−δ O4 型尖晶石固溶体中，通过热重分析研究了 1100、1200 和 1300 ∘C 下氧活度 aO2 的函数与化学计量的偏差 δ。实验结果（δ 与 log aO2 的 S 形曲线）针对不同条件下化学计量偏差中普遍存在的点缺陷类型进行了介绍和讨论。结论是，在高氧活度下，阳离子空位是主要的点缺陷，而在低氧活度下，阳离子填隙占主导地位。还讨论了点缺陷浓度的温度和成分依赖性。
Abstract The deviation from stoichiometry, δ, in spinel solid solutions of the type (TixFe1−x)3−δ O4 with x=0.1, 0.2 and 0.25 was studied thermogravimetrically as a function of oxygen activity, aO2, at 1100, 1200 and 1300 ∘C. The experimental results, S-shaped curves for δ vs. log aO2, are presented and discussed with regard to the type of point defects prevailing under different conditions in the deviation from stoichiometry. It is concluded that cation vacancies are the predominant point defects at high oxygen activities, while cation interstitials prevail at low oxygen activities. The temperature and composition dependencies of point defect concentrations are also discussed.