A New Model for Exchange of Deuterium in Oxide Ceramics for Protium in Light Water Molecule at Room Temperature.

For exchange of deuterium (D) in oxide ceramics for protium (H) in light water molecule at room temperature is proposed the one way diffusion model: absorption of proton and adsorption of OH- due to dissociation of H2O at the surface, diffusion of proton, release of deuteron in trapping site due to local molecular recombination with proton and the subsequent trapping of another proton into the vacant trapping site. The one way diffusion model has been formulated in form of the mass balance equations for free proton and both proton and deuteron trapped in trapping sites which include the rate constants of chemical reactions for proton described above. The solutions of the concentrations of deuterons retained and protons uptaken in the specimen have been fitted to the experimental data and the rate constants of the chemical reactions relevant to the D-H exchange have been determined. The rate constants of the chemical reactions are discussed. Moreover, potential applications of the one way diffusion model are discussed.