Raman Scattering Spectra of Carbon Materials Used as Cathodes of Auto-Emission Radiation Sources

Abstract

Structured carbon materials are widely used in engineering and scientific research, in particular as materials for the auto-emission cathode of cathodoluminescent lamps. We apply Raman spectroscopy to determine the effect on fine-grained graphite (MPG-6), pyrolytic graphite, and PAN fibers when used as cathodes. Raman scattering spectra of all three materials were recorded before and after in the spectral range from 1000 to 2000 cm–1. In addition to the main lines of G, D, and D’ of carbon materials, we found a line in the range of (1450–1460) cm–1 in the initial pyrolytic graphite, in pyrolytic graphite after use as a cathode, and in the MPG-6 sample after use as a cathode. We observed the greatest change in the relative integral intensity of line D in pyrolytic graphite and MPG-6. This intensity increased in pyrolytic graphite and decreased in MPG-6 after use as a cathode. It will be possible to use the relative integral intensity of line D to evaluate the operation of a cathodoluminescent lamp.