arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1502.07912cond-mat.mtrl-sci
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非晶锆英石中的固态扩散

Solid-state diffusion in amorphous zirconolite

C. Yang, E. Zarkadoula, M. T. Dove, I. T. Todorov, T. Geisler, V. V. Brazhkin, K. Trachenko

摘要:

我们讨论了结构无序和非晶化如何影响固态扩散,并考虑锆英石作为目前重要的案例研究。通过进行广泛的分子动力学模拟,我们解开的非晶化和密度的影响,并表明,固态扩散的深刻增加发生作为非晶化的结果。重要的是,这可以在与晶体相同的密度下发生,代表了关于固态扩散的有趣的一般见解。我们发现,在非晶系统中,降低密度会增加扩散常数的前置因子,但不会降低激活能。我们还发现,非晶化和密度变化对锆英石中的原子种类有不同的影响。我们的微观见解是相关的了解如何固态扩散的变化,由于无序和用于封装核废料的材料的操作建立预测模型。

英文摘要:

We discuss how structural disorder and amorphization affects solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but not decreasing the activation energy. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

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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