GALVANOMAGNETIC PROPERTIES OF LOW-DENSITY FOILS FABRICATED FROM EXFOLIATED GRAPHITE

We investigated the influence of the over-oxidation process on the res istivity and structure of graphite intercalation compounds with sulphu ric acid. Staging phenomena and amorphization were observed. The magne toresistance and Hall effect at low temperature of low density carbon foils, prepared from exfoliated graphite with different structural def ects were studied. The heat treatment temperature and time of oxidatio n appear to be the parameters which govern the degree of 3D or 2D orde ring in the carbon foils. The weak localization phenomenon for 2D elec tronic systems is invoked to explain the negative magnetoresistance as well as the low temperature dependence of the resistivity of samples.