MICROSCOPIC CHEMICAL-STATE IDENTIFICATION OF A SILICON-CARBIDE FIBER BY SOFT-X-RAY PHOTOABSORPTION SPECTROSCOPY

Chemical states of a 140 mu m silicon carbide fiber are determined by soft x-ray photo-absorption spectroscopy, using a magnetic projection photoelectron microscope, performed on the surface obtained by fractur ing. The spectrum of the carbon core of the fiber has prominent pi an d sigma resonance peaks and is very similar to that measured on highl y oriented pyrolitic graphite, indicating a graphitic nature of the ca rbon core. The spectrum of the silicon carbide coating of the fiber re veals similar features to those of single-crystal silicon carbide, ind icating that this coating is in the crystalline or polycrystalline pha se. (C) 1997 American Institute of Physics.