The permeation of O through a wafer sample was  measured at 1973 to 2033K, and the O permeability constant was determined. A data reduction scheme was used which could separate lattice diffusion, through the wafer, from other contributions. The experimental data were in agreement with previously reported data for Ca-stabilized zirconia and alumina. The O permeability constant of Y2SiO5 at 1973K was 10-10kg/m-s. The O transport mechanism was considered with regard to the activation energy for O permeation, and the relationship between O permeability and O partial pressure. The experimental results indicated that vacancy diffusion predominated below 1913K, while interstitial diffusion was dominant above 1913K. It was suggested that there was a mechanism which involved a change from vacancy diffusion to interstitial diffusion with increasing temperature. Interstitial diffusion was not expected to be active at higher temperatures.

Oxygen Permeability of Y2SiO5. Y.Ogura, M.Kondo, T.Morimoto, A.Notomi, T.Sekigawa: Materials Transactions, 2001, 42[6], 1124-30