  This work reports the peculiar properties of a graphene film prepared by the
chemical vapor deposition (CVD) of ethylene in high vacuum on a well oriented
and carefully cleaned Pt(111) crystal surface maintained at high temperature.
In-situ and ex-situ characterization techniques (low energy electron
diffraction, high resolution electron energy loss spectroscopy, scanning
electron microscopy and Raman micro-spectroscopy) used here indicate the
prevalence of single layer regions and the presence of two different
orientations of the graphene sheets with respect to the Pt(111) substrate. In
most of the deposited area evidence is found of a compressive stress for the
graphene lattice, as a net result of the growth process on a metal substrate.
This graphene film grown on Pt(111) exhibits a lower degree of order and of
homogeneity with respect to the exfoliated graphene on Si/SiO2, as it is found
generally for graphene on metals, but several characterization techniques
indicates a better quality than in previous deposition experiments on the same
metal substrate.
