Transport Properties of Disordered Graphene Layers

Samples consisting of a few layers of graphene obtained by thermal decomposition of SiC were studied by means of transport experiments at 4 K and in a magnetic field up to 7 T. Transport data show that the samples have a two-dimensional character. Magnetoresistance has an approximately linear character at high magnetic fields, which has been previously observed in graphite samples, and a negative magnetoresistance, at low magnetic fields. The transverse resistivity $ρ_{xy}$ is nonlinear as a function of B, which can be described using a many-carrier model.