Measurement of the surface resistivity and electrical conductivity of carbon nanotube sheets using the resonant post-method

The dielectric post-resonant measurement method is extended to characterize the conduction properties of carbon nanotube sheets in the GHz frequency range (3GHz<f<20GHz) without the need for external contacts or the necessity of carbon coating. Three low-loss reference dielectrics (_TiO2, _BaTi4O9, Teflon) with known dielectric properties are used. Conductivity values of various metals (steel, lead, brass, aluminium, copper) of the order 10⁶-10⁷ S/m were measured to show the suitability of the method. The electrical conductivity of the carbon nanotube sheets could be determined to approximately 1.7·10⁵ S/m.