Surface degradation of glass measured by nanoindentation

Abstract Nanoindentation tests at the maximum loads P max = 50 and 10 μN were conducted to examine the surface degradation of two glasses: alkaline-earth aluminosilicate as-fused glass for a liquid-crystal substrate and mechanically polished optical lead F-1 glass. The load P-penetration depth h curve for the substrate glass followed an ideal square power law, while that for the F-1 glass deviated from the square power law at the initial stage up to h = 6.0nm. X-ray photoelectron spectroscopy revealed that O—H bonds were formed on the surface of the F-1 glass, suggesting the occurrence of degradation, while no O—H peak was detected on the surface of substrate glass.