Pyrolytic carbon layers—an electron spin resonance analysis

Abstract Chemical vapour infiltration is simulated by deposition of pyrolytic carbon on planar boron nitride substrates and carbon fibers in a hot-wall tubular reactor at about 1100 °C for varied pressure and flow-velocity of methane. The degree of orientation of the deposited graphite-like domains can be monitored via orientation and temperature dependence of the electron spin resonance parameters (g-tensor, linewidth). The electronic structure of the localized defects and conduction electrons is accessible by a quantitative modelling of these parameters. The interaction of the built-in hydrogen atoms with the unpaired electron spins is analysed by electron–proton spin double resonance technique (Overhauser shift)