  In this article, based on first-principles calculations, we systematically
study functionalization induced diamonization of graphene bilayer and
graphene-BN hybrid bilayer. With single-side functionalization, the diamondized
structures are magnetic semiconductor. Interestingly, if both sides of the
bilayer are functionalized, diamondization becomes spontaneous without a
barrier. On the other hand, when the bottom layer of the bilayer graphene is
replaced by a single hexagonal BN layer, the diamondized structure becomes
nonmagnetic metal. The tunable electronic and magnetic properties pave new
avenues to construct graphene-based electronics and spintronics devices.
