Interactions of carbon and oxygen on glass surfaces

Interactions between carbon and oxygen on glass surfaces under heat treatments have been observed in x-ray photoelectron spectroscopy (XPS) measurements. The reactions of carbon and oxygen on surfaces were monitored by the binding energies of photoelectrons emitted from 1s states of carbon and oxygen. A single XPS C1 s peak was broadened and two peaks were clearly resolved after the sample was silica heated above 250°C. These two-component carbon peak positions were analyzed through the curve fitting technique. Not only the ratio of high-binding and low-binding peaks of C1 s but also the relative peak positions were changed with the sample temperature and the period of heat treatment. Comparison studies on the oxygen 1s peak also showed the development of two component peak. The relative concentrations of two peaks changed with sample temperature and the duration of heat treatment. The two-component peaks appeared in C1 s as well as in Ol s ′ which strongly indicates that bonds between carbon and oxygen are formed during sample heating.