LAUSR

The formation of gas-filled bubbles, which is one of the indicators and quantitative criteria for radiation degradation of the surface layer of K-208 glass irradiated by 20-keV electrons, and the effect of ITO (Indium tin oxide) film deposited on the glass, are investigated. Using atomic force microscopy, the nucleation of oxygen bubbles in the surface layer of glass irradiated with a fluence (Φ) of the order of 1015 cm–2 at a particle flux density (φ) of 2·1010 cm–2·s–1 was detected. Gas-filled bubbles appear on the surface of samples with an ITO film at Φ ≥ 4·1015 cm–2 in smaller amounts but larger sizes than on glass without a film. The formation of oxygen bubbles is explained by the formation of a negative charge region in the surface layer of the irradiated glass, in the field of which sodium ions migrate, which plays a key role in the release of non-bridge oxygen atoms. Migration and aggregation of liberated oxygen atoms in defective places in the glass grid leads to the formation of gas-filled bubbles.