Influence of rhombohedral stacking order in the electrical resistance of bulk and mesoscopic graphite

摘要

The electrical, in-plane resistance as a function of temperatureR(T ) of bulk and mesoscopic thin graphite flakesobtained from the same batch was investigated. Samples thicker than ～30 nm show metalliclike contribution in atemperature range that increases with the sample thickness, whereas a semiconductinglike behavior was observedfor thinner samples. The temperature dependence of the in-plane resistance of all measured samples and severalothers from literature can be very well explained between 2 and 1100 K assuming three contributions in parallel:a metalliclike conducting path at the interfaces between crystalline regions, composed of two semiconductingphases, i.e., Bernal and rhombohedral stacking. From the fits of R(T ) we obtain a semiconducting energy gapof 110 ± 20 meV for the rhombohedral and 38 ± 8 meV for the Bernal phase. The presence of these crystallinephases was confirmed by x-ray diffraction measurements.We review similar experimental data from literature ofthe last 33 years and two more theoretical models used to fit R(T ).