Galvanomagnetic properties of low density foils fabricated from exfoliated graphite

Abstract

We investigated the influence of the over-oxidation process on the resistivity and structure of graphite intercalation compounds with sulphuric acid. Staging phenomena and amorphization were observed. The magnetoresistance and Hall effect at low temperature of low density carbon foils, prepared from exfoliated graphite with different structural defects were studied. The heat treatment temperature and time of oxidation appear to be the parameters which govern the degree of 3D or 2D ordering in the carbon foils. The weak localization phenomenon for 2D electronic systems is invoked to explain the negative magnetoresistance as well as the low temperature dependence of the resistivity of samples.