Influence of rhombohedral stacking order in the electrical resistance of   bulk and mesoscopic graphite
  The electrical, in-plane resistance as a function of temperature $R(T)$ of bulk and mesoscopic thin graphite flakes obtained from the same batch was investigated. Samples thicker than $\sim 30$ nm show metalliclike contribution in a temperature range that increases with the sample thickness, whereas a semiconductinglike behavior was observed for thinner samples. The temperature dependence of the in-plane resistance of all measured samples and several others from literature can be very well explained between 2 K and 1100 K assuming three contributions in parallel: a metalliclike conducting path at the interfaces between crystalline regions, composed of two semiconducting phases, i.e. Bernal and rhombohedral stacking. From the fits of $R(T)$ we obtain a semiconducting energy gap of $110 \pm 20$meV for the rhombohedral and $38\pm 8 $meV for the Bernal phase. The presence of these crystalline phases was confirmed by x-ray diffraction measurements. We review similar experimental data from literature of the last 33 years and two more theoretical models used to fit $R(T)$. 
M. Zoraghi, J. Barzola-Quiquia, M. Stiller, A. Setzer, P. Esquinazi,   G. H. Kloess, T. Muenster, T. L\"uhmann and I. Estrel...
cond-mat.mtrl-sci