Effect of microstructure change on the deuterium permeation properties of erbium oxide coatings prepared via MOCVD

The effect of microstructure on the deuterium permeation inhibition properties of Er2O3 coatings was investigated. Coatings were prepared by metal organic chemical vapor deposition (MOCVD) followed by annealing at 700 °C or 800 °C. The coating annealed at 700 °C exhibited a more compact structure than the as-deposited coating and the coating annealed at 800 °C. The hydrogen permeation inhibition performance of coatings was investigated by deuterium permeation measurement. The most compact 700°C-prepared coating also exhibited the best permeation inhibition performance. Furthermore, large cracks and holes appeared on the coating annealed at 800 °C after the permeation measurement, suggesting too high annealing temperature could result in more structural defects, leading to poorer mechanical integrity and inhibition performance. X-ray photoelectron spectroscopic analysis indicated that the oxygen/erbium ratio of the coating annealed at 700 °C corresponded closely to the stoichiometric ratio.