Abstract
Structural, electrical and morphological properties of electrical conducting nanoporous carbon structures, prepared at different pyrolysis temperatures by sol–gel method, were investigated. The effect of the measurement temperature on the electrical properties of the obtained sample pyrolysed at 675°C was studied. The imaginary and real parts of the sample impedance versus frequency, in the range of 40Hz–100MHz, are investigated. The Nyquist diagrams were used to identify an equivalent circuit and the fundamental parameters of the circuit are determined at different temperatures with the aim to study the contributions of the grains and boundary grains to the conductivity.
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► Nanocarbon structures based on RF were synthesized via sol–gel route using L. El Mir protocol. ► Structural, electrical and morphological properties were investigated. ► It has been shown that dc and ac conductivities can be both attributed to bulk hopping transport. ► The V–I characteristics, resulting from NDR phase, has been found to follow the relationship V–I−β.