Dielectric constants of single-wall carbon nanotubes at various frequencies.

A cylindrical rod composed of a uniform mixture of single-wall carbon nanotubes and alumina powders dissolved in paraffin was inserted in the center of a radio frequency cavity. The complex dielectric constant of carbon tubes at various frequencies was measured by a resistance-inductance-capacitance (RLC) meter and a microwave network analyzer. The cylindrical rod benefits the protection of the sample from adsorbing moisture and preventing the rod from filling with air, thus making accuracy experiment values. The real part and the imaginary part of the dielectric constants of single-wall carbon nanotubes are, respectively, increase and decrease in magnitudes as frequency increases satisfactorily in complying with the portray from the free electron Drude model.