The diffusion of water in oxides was modelled as resulting from the solution and diffusion of molecular water in the oxide. This dissolved water could react and exchange with the oxide network so as to form immobile OH groups plus various H and O isotopes in the oxide. The results agreed with many experiments on water diffusion in oxides. The activation energy for the diffusion of water in oxides was related to the structural open-ness of the oxide; thus suggesting that molecular water was the diffusing species.

Diffusion of Water in Crystalline and Glassy Oxides - Diffusion-Reaction Model. R.H.Doremus: Journal of Materials Research, 1999, 14[9], 3754-8