Thermodiffusion and ion transport in doped ceria by molecular dynamics simulations
Thermodiffusion and ion transport in doped ceria by molecular dynamics simulations
复制标题
通过分子动力学模拟掺杂二氧化铈中的热扩散和离子传输
DOI：
10.1016/j.actamat.2021.116802
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
G. Murch
中科院分区：
文献类型：
--
作者：
S. Grieshammer;I. Belova;G. Murch
我们用分子动力学方法模拟了掺杂CeO_2的热扩散和离子电导。利用氧离子的自相关函数和集体位移、由均方位移量得到的示踪剂扩散系数和电场中的位移来估算离子电导率的四种方法。用格林-久保方法确定了Onsager输运矩阵的质-热耦合交叉系数L OQ和L QO。这是第一次计算离子化合物中的这些系数。模拟的参数在整个温度范围内都是负值，这表明阴离子在温度梯度中从冷区到热区的净迁移。研究结果强调了氧离子电解液中的传质和传热之间的耦合可能会对实际应用产生影响。
We simulated thermodiffusion and ionic conductivity in doped ceria by molecular dynamics. Four approaches to estimate the ionic conductivity were applied using the auto-correlation function and collective displacement of oxygen ions, the tracer diffusion coefficient from the mean squared displacement, and the displacement in an electric field. The Green-Kubo method was applied to determine the mass-heat coupling cross-coefficients L Oq and L qO of the Onsager transport matrix. This is the first calculation of these coefficients in an ionic compound. The simulated parameters are negative throughout the applied temperature range suggesting net transport of anions from a cold to a hot region in a temperature gradient. The results emphasize that the coupling between mass and heat transport in an oxygen ion electrolyte could have an impact for practical applications.