A yttrium layer was electrodeposited on the surface of PAN-based carbon fibers in yttrium nitrate ethanol solution,and the corresponding morphology of the yttrium layer was investigated through scan electron microscopy.The loading mass of the yttrium on the surface of PAN-based carbon fibers was controlled by the charge during the electrochemical deposition.The effect of yttrium on catalytic graphitization of PAN-based carbon fibers was investigated by X-ray diffraction(XRD).The mean crystallite size(Lc) an...