Influence of magnetic fields on the two-dimensional electron transport in weakly disordered fluorine-intercalated graphite fibers.

Abstract

We report measurements of the temperature dependence of the resistivity in zero magnetic field and in magnetic fields up to 5 tesla for weakly disordered fluorine-intercalated graphite fibers (${\mathrm{C}}_{\mathit{x}}$F) with various fluorine concentrations (3.6x5.8). These results have been used to determine the importance of weak localization and carrier-carrier interaction in these two-dimensional (2D) systems. We found that both quantum phenomena contribute to the logarithmic increase of resistivity with decreasing temperature, though the interaction effect is generally dominant. Also, the magnitude of the resistivity increase is very sensitive to the fluorine concentration. The temperature dependence of the inelastic scattering rate 1/${\mathrm{\ensuremath{\tau}}}_{\mathit{i}}$, as obtained from magnetoresistance measurements, is well fitted by a polynomial expression of the form ${\mathrm{\ensuremath{\tau}}}_{\mathit{i}}^{\mathrm{\ensuremath{-}}1}$=\ensuremath{\alpha}T+\ensuremath{\beta}${\mathit{T}}^{2}$. The linear term ${\mathrm{\ensuremath{\tau}}}_{\mathit{i}}^{\mathrm{\ensuremath{-}}1}$(T) exhibits a good quantitative agreement with the theoretical prediction for the expected disorder dependence of the carrier-carrier scattering in 2D disordered metals.