  We show within a local self-consistent mean-field treatment that a random
distribution of magnetic adatoms can open a robust gap in the electronic
spectrum of graphene. The electronic gap results from the interplay between the
nature of the graphene sublattice structure and the exchange interaction
between adatoms.The size of the gap depends on the strength of the exchange
interaction between carriers and localized spins and can be controlled by both
temperature and external magnetic field. Furthermore, we show that an external
magnetic field creates an imbalance of spin-up and spin-down carriers at the
Fermi level, making doped graphene suitable for spin injection and other
spintronic applications.
