• 文献标题:   On the sign of the relaxation activation energy for interfacial polarization in reduced graphene oxide-based nano-composites
  • 文献类型:   Article
  • 作  者:   ISLAM R, PAPATHANASSIOU AN, CHANYUKING R, ROUSSEL F
  • 作者关键词:  
  • 出版物名称:   APPLIED PHYSICS LETTERS
  • ISSN:   0003-6951 EI 1077-3118
  • 通讯作者地址:   Univ Lille Sci Technol
  • 被引频次:   6
  • DOI:   10.1063/1.4966273
  • 出版年:   2016

▎ 摘  要

The dielectric relaxation mechanism associated with the interfacial polarization in polyaniline/reduced graphene oxide (PANI/RGO) nano-composites is found to shift towards lower frequencies on increasing temperature. Accordingly, the effective activation energy value is negative. Basic concepts of the Sillars dielectric theory of a heterogeneous medium are revisited for a material consisting of conducting platelets dispersed in a semi-insulating matrix in order to explain the negative sign of the relaxation energy. A plausible explanation to this observation involves a thermally activated detrapping mechanism through the effective potential barrier at the interfaces between RGO and PANI. This results in an enhancement of the density of charge carriers which contributes to dc conductivity at the expense of the density of charge carriers that relax within RGO inclusions. Subsequently, the intensity of the dielectric peak is suppressed on heating which results in a systematic modification of the shapes of the dc conductivity vs temperature curves. Published by AIP Publishing.