Electrical conductivity and dielectric constant of heat-treated polyacrylonitrile in an AC regime

Autor: G Bordure, A Ardalan, J.L Jacquemin
Rok vydání: 1978
Předmět:
Zdroj: Journal of Non-Crystalline Solids. 28:249-257
ISSN: 0022-3093
DOI: 10.1016/0022-3093(78)90011-x
Popis: The electrical conductivity σ(ω) and the dielectric constant ϵ(ω) of heat-treated polyacrylonitrile (PAN) samples obtained by pyrolysis at temperatures up to 550°C, were measured in the frequency range from 500 Hz to 250 MHz at room temperature. For samples treated at temperatures below 300°C and for frequencies up to 200 MHz, the conductivity obeys a ω s law ( s = 1) while ϵ does not change significantly. For heat-treatment temperatures above 300°C, the behaviour of σ(ω) is greatly modified. In fact, ϵ(ω) greatly increases at low frequencies for increasing heat-treatment temperatures, and is strongly dependent frequency. Our results can be explained with the help of two randomly distributed phases in the medium and by introducing percolation theory.
Databáze: OpenAIRE
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