Using first principles electronic structure calculations we screen nine elements for their potential to retard oxygen diffusion through poly-crystalline Pt (p-Pt) films. We determine that O diffuses preferentially as interstitial along Pt grain boundaries (GBs). The calculated barriers are compatible with experimental estimates. We find that Be controls O diffusion through p-Pt. Beryllium segregates to Pt GBs at interstitial (i) and substitutional (s) sites. i-Be is slightly less mobile than O and it repels O, thus stuffing the GB. s-Be has a high diffusion barrier and it forms strong bonds to O, trapping O in the GB. Experiments confirm our theoretical predictions.
Cite
@article{arxiv.cond-mat/9903082,
title = {Reduced O diffusion through Be doped Pt electrodes},
author = {Roland Stumpf and Clarence Tracy},
journal= {arXiv preprint arXiv:cond-mat/9903082},
year = {2009}
}