The diffusion of 18O was studied in 37.2wt%K2O samples by using a gaseous exchange technique at 820 to 902C. The tracer diffusion data were described by:

D (cm2/s) = 1.7 x 101 exp[-59.7(kcal/mol)/RT]

For O partial pressures of 5.6 to 42.2cmHg, at 902C, the diffusivity was independent of the pressure. The O transport mechanism was suggested to involve reversible dissociation. At 820 to 873C, under an O partial pressure of 5.6cmHg and a partial water-vapor pressure of 1cmHg, the diffusivity was described by:

D (cm2/s) = 5.4 x 100 exp[-56.8(kcal/mol)/RT]

K.C.De Berg, I.Lauder: Physics and Chemistry of Glasses, 1980, 21[3], 106-9