Linear and nonlinear conductivity spectra of tetraethylene oxide organosiloxane copolymer LiClO4 complex

The temperature dependence of the frequency spectra of linear to third-order nonlinear complex conductivities in tetraethylene oxide-organosiloxane copolymer/LiClO4 complexes was measured. At each temperature, a characteristic conduction relaxation phenomenon was observed in the spectra, which suggested the existence of different ion conduction mechanisms between the low-and high-frequency regions. We found that the ratio of linear to nonlinear conductivities was closely related to the elementary process of ionic transport in the samples. Without the need for any additional assumptions, we also found that the ratio obtained from nonlinear measurements allowed an estimate of the important parameters which characterize ionic transport in the samples, such as the size of a connected cluster of the site capable of ion hopping or the hopping distance of ion. (C) 1998 Elsevier Science B.V. All rights reserved.