▎ 摘　　要

We directly compare the effect of metallic titanium (Ti) and insulating titanium dioxide (TiO(2)) on the transport properties of single layer graphene. The deposition of Ti results in substantial n-type doping and a reduction in graphene mobility by charged impurity scattering. Subsequent exposure to oxygen largely reduces the doping and scattering by converting Ti into TiO(2). In addition, we observe evidence for short-range scattering by TiO(2) impurities. These results illustrate the contrasting scattering mechanisms for identical spatial distributions of metallic and insulating adsorbates. (C) 2011 American Institute of Physics. [doi:10.1063/1.3588035]