Graphene on epitaxial ferro- electric BaTiO3 : an atomistic study

DALOSTO, SERGIO; TINTE, SILVIA

Buenos Aires

Workshop; At the Frontiers of Condensed Matter V; 2010

CNEA

The exceptional electrical properties of graphenehave made it a promising material for device appli-cations, such as field effect transistors. However itsintrinsic high mobility can be degraded when it issupported on a dielectric substrate, as the widelyused SiO2 , due to the substrate surface properties.Recently it was reported that graphene mobility in-creases when SiO2 is replaced by a ferroelectric mate-rial, which is characterized by a reversible nonvolatileelectric polarization. Here we study the interaction ofa graphene nanodot with the film surface of the proto-typical ferroelectric BaTiO3 using atomistic modelingthrough Molecular Dynamics simulations performedat room temperature. The ferroelectric film is un-der bi-axial compressive strain presenting a tetragonal(001)-oriented phase, and domains with electric po-larization pointing towards and inwards the surface.Binding energies for graphene dots of different sizesdepending on the polarizations and boundaries of thedomains are reported.