Analysis of surface oxidation behavior at 500 °C under dry air of glass-like carbon heat-treated from 1200 to 3000 °C

The Surface oxidation behavior at 500 °C under dry air of glass-like carbons heat-treated from 1200 to 3000 °C was investigated by thermogravimetric analysis (TGA), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the oxidation rate of specimens heat-treated above 2000 °C was much slower than the rate of those heat-treated below 1500 °C and varies with the heat treatment temperature of the carbons. Raman spectroscopy revealed that the developed graphite structure of the carbons did not dominate the rates. It was inferred by XPS that the carbon bonded to oxygen in the internal region as well as that on the external surface was easily oxidized. The heat treatment temperature for preventing oxidation was above 2000 °C.