Electrical Transport Properties of Carbon Aerogels

Carbon aerogels are prepared by sol-gel polymerization and supercriticle drying. By controlling the mass ratio of reactants and the molar ratio of resorcinol to catalyst (R/C), carbon aerogels with different microstructure can be developed. Hall effect is measured by Van der Bow method. The results show that the electrical conductivity increases with increasing density of carbon aerogel, and Hall mobility at high temperature is nearly constant, while at low temperature the absolute value of Hall mobility increases linearly with decreasing temperature. The abnormal sign of Hall mobility is probably related to the microstructure of carbon aerogels, which influence the transport path of carriers.