Oxygen self-diffusion in a potassium strontium silicate glass using proton activation analysis

Abstract

Oxygen self-diffusion coefficients were measured in a 20K₂O-20SrO-60SiO₂ (wt%) glass above and below the glass transition temperature using the single spectrum proton activation analysis of oxygen-18 using the nuclear reaction ¹⁸O(p, α)¹⁵N. The α-particle spectrum recorded during proton irradiation is used to determine the ¹⁸O concentration profile. The self-diffusion coefficients, D, determined for the three diffusion times of about 22 h, 3 1/2 and 7 1/2 days were in good agreement within experimental error, except for the two lowest temperatures of the short-time run possibly because of the shallow depths of diffusion and surface exchange. In the temperature range 600 to 1000 K, D values with the relations, above the glass transition temperature D=7.6×10¹⁴ exp(−119 kcal/RT) cm²sec⁻¹, and below the glass transition temperature D=1×10⁻¹² exp(−10 kcal/RT) cm²sec⁻¹, were obtained.