The temperature dependence of the dc conductivity for polyamide-imide films, implanted with 50 keV As ions to different fluences, has been studied. Our high-resolution data reveal a two-component conductivity that depends on both one-dimensional variable range hopping (VRH) and three-dimensional VRH. For low fluence levels (5×1015 ions/cm2), the one-dimensional VRH is dominant while at higher fluences (1×10 17 ions/cm2), the three-dimensional VRH dominates. These materials become highly disordered and form hard carbon materials along the ion track. The conductivity may be explained by 1D VRH along the ion track at low fluences while at higher fluences, regions of carbon rich material form three-dimensional structures where 3D VRH exists. This rather simple model and its composite conductivity can explain the exact curvature of the temperature dependent conductivity, while single VRH models and percolation models cannot.
Physics, Astronomy, and Materials Science
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics and may be found at https://doi.org/10.1063/1.353824.
Wang, Yongqiang, L. B. Bridwell, and R. E. Giedd. "Composite conduction in ion‐implanted polymers." Journal of applied physics 73, no. 1 (1993): 474-476.
Journal of Applied Physics