Solid-State Chemistry on the Nanoscale: Ion Transport through Interstitial Sites or Vacancies?
Solid-State Chemistry on the Nanoscale: Ion Transport through Interstitial Sites or Vacancies?
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DOI：
10.1002/anie.201507263
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发表时间：
2015-11-16
影响因子：
16.6
通讯作者：
Weller, Horst
中科院分区：
文献类型：
--
作者：
Bothe, Cornelia;Kornowski, Andreas;Weller, Horst
在不改变尺寸和形状的情况下，纳米晶体中的离子交换过程如何发生？为什么离子传输比粗晶固体中的经典相互扩散过程快得多？我们通过高分辨率分析电子显微镜在几个模型反应的温度依赖性动力学实验中在分子水平上研究了这些过程。结果清楚地表明扩散过程仅通过间隙晶格位置进行，随后“踢出”以从晶格位置去除单个离子，而不形成空位。以前在纳米晶系统中尚未观察到这种机制。
How can ion-exchange process occur in nanocrystals without the size and shape changing and why is the ion transport much faster than in classical interdiffusion processes in macrocrystalline solids? We have investigated these processes at the molecular level by means of high-resolution and analytical electron microscopy in temperature-dependent kinetic experiments for several model reactions. The results clearly show a diffusion process that proceeds exclusively through the interstitial lattice positions with a subsequent "kick out" to remove individual ions from lattice sites without the formation of vacancies. This mechanism has not been observed in nanocrystalline systems before.