Relations between sp~2 hybrid C—C bond length and structure parameters of PAN-based carbon fibers

PAN-based carbon fibers with different carbonization temperatures were characterized by Raman scattering and X-ray diffraction. The length of the sp~2 hybrid C—C bond was obtained on the basis of Fitzer's C—C bond length formula. Structural parameters (L_a, L_c, d_(002)) of graphite were obtained by X-ray diffraction measurements. The dependences of sp~2 hybrid C—C bond length with structural parameters (L_a, L_c, d_(002)) were obtained. It was found that sp~2 hybrid C—C bond length increases with L_a, L_c and decreases with d_(002).