PAN基炭纤维中SP^2杂化的C—C原子键距对电阻率影响的研究

THE EFFECT OF BOND LENGTH OF C-C ATOMS WITH SP^2 HYBRIDIZATION ON THE ELECTRICAL RESISTIVITY IN PAN-BASED CARBON FIBER

利用激光Raman散射方法,从Fitzer碳键键距出发,得到不同碳温度下制备的PAN基炭纤维样品中SP^2杂化的C-C原子键距a_0。利用四点法对各样品的电阻率进行了测试,给出了电阻率随C—C原子键距a_0的变化规律,并对这种变化规律从电子结构角度进行了初步探讨。结果表明,SP^2杂化的共价电子向传导电子的转移及结构发展的更完善共同导致了PAN基炭纤维的电阻率随碳化温度的升高而降低。

The samples of PAN-based carbon fiber with different carbonization temperatures are measured using laser Raman scattering method. Bond length of C-C atoms with SP2 hybridization is given on the basis of Fitzer's C-C bond lengthao formula,and resistivitr of all samples are measured using a four point method. Relation between bond lengthao of C-C atoms with SP2 hybridization and carbonization temperature is given. The reason which resistivity decreases with increasing carbonization temperature is discussed from electronic structure. It is given that resistivity decreaseing with increasing carbonization temperature result from transference of electron pairbond with SP2 hybridization to transferable electron and perfect degree of turbostratic graphite structure.