Rushton M J D, Chroneos A
Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom.
1] Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom [2] Faculty of Engineering and Computing, Coventry University, 3 Gulson Street, Coventry CV1 2JH, UK.
Sci Rep. 2014 Aug 14;4:6068. doi: 10.1038/srep06068.
Doped ceria is an important electrolyte for solid oxide fuel cell applications. Molecular dynamics simulations have been used to investigate the impact of uniaxial strain along the <100> directions and rare-earth doping (Yb, Er, Ho, Dy, Gd, Sm, Nd, and La) on oxygen diffusion. We introduce a new potential model that is able to describe the thermal expansion and elastic properties of ceria to give excellent agreement with experimental data. We calculate the activation energy of oxygen migration in the temperature range 900-1900 K for both unstrained and rare-earth doped ceria systems under tensile strain. Uniaxial strain has a considerable effect in lowering the activation energies of oxygen migration. A more pronounced increase in oxygen diffusivities is predicted at the lower end of the temperature range for all the dopants considered.
掺杂二氧化铈是用于固体氧化物燃料电池的一种重要电解质。分子动力学模拟已被用于研究沿<100>方向的单轴应变以及稀土掺杂（镱、铒、钬、镝、钆、钐、钕和镧）对氧扩散的影响。我们引入了一种新的势模型，该模型能够描述二氧化铈的热膨胀和弹性特性，从而与实验数据达成极佳的吻合。我们计算了在900 - 1900 K温度范围内，未应变和稀土掺杂的二氧化铈体系在拉伸应变下氧迁移的活化能。单轴应变在降低氧迁移活化能方面有显著作用。对于所有考虑的掺杂剂，预计在温度范围的低端氧扩散率会有更明显的增加。
