The problem of calculating the diffusivities of gases in molecular sieves from experimental sorption curves is discussed. Commercial molecular sieve pellets contain zeolite crystallites of various sizes and it is shown that both the shape and the size distribution of the crystallites have significan
A Molecular Dynamics Study on the Oxygen Diffusion in Doped Fluorites: The Effect of the Dopant Distribution
✍ Scribed by A. Tarancón; A. Morata; F. Peiró; G. Dezanneau
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 957 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1615-6846
No coin nor oath required. For personal study only.
✦ Synopsis
The effect of the dopant distribution on the oxygen diffusion in doped fluorites typically used for solid oxide fuel cells electrolyte applications has been analysed by using molecular dynamics simulations. The oxygen mass transport in both yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria has been studied and compared in the range of temperatures between 1,159 and 1,959 K. A new methodology based on the analysis of local environments is used to describe the diffusion process at an atomic scale. Preferred vacancy migration pathways, most suitable conduction models, energy landscapes and jump efficiency have been detailed for each material. Finally, a particular case of nonrandom distribution of dopants in YSZ is presented in order to quantitatively evaluate the effect of the dopant pattern on the mass transport properties and the potential of the methodology developed here for understanding and foreseeing real configurations at the nanoscale.
📜 SIMILAR VOLUMES
## Abstract Phosphorothioate oligonucleotides (PS–ODNs) have gained considerable attention in drug therapy, primarily as potent antisense or antigene oligomers, which bind to specific DNA or mRNA sequences and lead to transcriptional or translational arrest. These are obtained by substituting one o
Comprehensive theoretical studies have been made on the effect of initiation and transfer to monomer on the molecular size distribution in living polymers. However, no detailed theoretical investigation involving spontaneous transfer has been reported so far. In the present paper, a study is made of