Gamma-ray-induced migration of hydrogen isotopes in zirconium oxide coatings at room temperature

Hydrogen in materials is scientifically and technologically critical due to its unique behavior and large impact on material properties. Here, we report the migration of hydrogen isotopes in ceramic coatings induced by gamma-ray irradiation at room temperature. Nuclear reaction analysis performed simultaneously on hydrogen and deuterium reveals that residual hydrogen isotope impurities in zirconium oxide coatings fabricated by metal organic decomposition exist in the form of both stable and mobile species, whereas coatings made by magnetron sputtering contain only stable ones. The concentrations of mobile hydrogen and deuterium in the coating interior decrease significantly with the gamma-ray dose, whereas those of the stable species do not. An external hydrogen gas atmosphere prevents the depletion of mobile hydrogen and deuterium during the irradiation. This work opens a new strategy to transport and remove hydrogen isotopes from materials without elevated temperature.