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Reduced O diffusion through Be doped Pt electrodes

Roland Stumpf·Clarence Tracy
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Abstract

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.

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Roland Stumpf, Clarence Tracy. 1999-03-04. Reduced O diffusion through Be doped Pt electrodes. https://doi.org/10.1063/1.124703

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