Agradecimentos: This work was supported by the Deutsche Forschungsgemeinschaft under Contract DFG ES 86/16-1 and by the DAAD Project No. 56269524 under PROBRAL and CAPES. R.R.d.S. and Y.K. acknowledge the support from FAPESP, CNPq, CAPES-PNPD 1571/2008, ROBOCON, and INCT NAMITEC. A.B. and S.D. were supported by the Graduate School of Natural Sciences "Build-MoNa" of the University of Leipzig and ESF-NFG and ESF "Energie" from the European Fonds for the state of Saxony Ver menos

Abstract: The carrier density in tens of nanometers thick graphite samples (multi-layer-graphene, MLG) has been modified by applying a gate voltage (V-g) perpendicular to the graphene planes. Surface potential microscopy shows inhomogeneities in the carrier density (n) in the sample near surface region and under different values of V-g at room temperature. Transport measurements on different MLG samples reveal that under a large enough applied electric field these regions undergo a superconducting-like transition at T less than or similar to 17K. A magnetic field applied parallel or normal to the graphene layers suppresses the transition without changing appreciably the transition temperature Ver menos