Effect of water incorporation on the diffusion of sodium in Type I silica glass

Incorporation of water into glasses and its influence on the diffusion of cations, including the creation of diffusion barriers

“…From previous studies related to the diffusion of sodium in a Type I silica glass, Infrasil 302 [7], and in an alkalineearth boroaluminosilicate glass, Corning Code 1737 [8], it is known that these glasses incorporate water when annealed at elevated temperatures in moist atmospheres. Details about the two glasses denoted above, including their chemical compositions, impurity levels and strain points, can be found in Refs.…”

“…Details about the two glasses denoted above, including their chemical compositions, impurity levels and strain points, can be found in Refs. [7][8][9]. To verify that the glasses denoted above take up water during high temperature annealing, glass samples were annealed for different times in moist air.…”

“…To verify that the glasses denoted above take up water during high temperature annealing, glass samples were annealed for different times in moist air. For Type I silica glass, the water uptake was studied at 1000°C in common air and in air saturated with water at 80°C [7] and for the alkaline-earth boroaluminosilicate glass denoted above in air saturated with water at 80°C at 650, 700 and 800°C [8]. Fig.…”

“…The mathematics related to these cases has been worked out; the proper equations for c i (n, t) and their derivations, as well as equations giving the normalized residual radioactivities related to c i (n, t) have been reported in Ref. [7] for Case B and in Ref. [8] for Case C.…”

“…3. Examples for Case A residual radioactivity profiles observed for the diffusion of Na-22: (a) in an as-received Type I silica glass sample diffusionannealed at 650°C in common air [7], and (b) in a sample of the earth-alkaline boroaluminosilicate glass Corning Code 1737 diffusion-annealed at 650°C in common air [8]. If D ns = D bu , Eqs.…”