AVS 60th International Symposium and Exhibition
    Graphene and Other 2D Materials Focus Topic Wednesday Sessions
       Session GR-WeM

Paper GR-WeM12
Growth Kinetics of Monolayer Graphene on Pd(111)

Wednesday, October 30, 2013, 11:40 am, Room 104 B

Session: 2D Materials on Metallic Substrates
Presenter: S. Kodambaka, University of California at Los Angeles
Authors: H.S. Mok, University of California at Los Angeles
A. Ebnonnasir, Colorado School of Mines
S. Nie, Sandia National Laboratories
N.C. Bartelt, Sandia National Laboratories
K.F. McCarty, Sandia National Laboratories
C.V. Ciobanu, Colorado School of Mines
S. Kodambaka, University of California at Los Angeles
Correspondent: Click to Email
Using in situ low energy electron microscopy (LEEM) observations along with density functional theory (DFT) calculations, we investigated the growth kinetics of monolayer graphene on Pd(111). All of our experiments were carried out on carbon-containing Pd(111) single crystals. Graphene layers were grown by cooling the sample to temperatures below 900 oC during annealing the sample in ultra-high vacuum. LEEM images and electron reflectivity data were acquired during graphene growth as a function of incident electron energy and annealing time. From the LEEM images, we measured the time-dependent changes in areas of graphene islands. From the electron reflectivity data, we determine the work functions of graphene-covered and graphene-free regions on the surface as a function of time. Interestingly, the work functions of graphene-free regions decrease (increase) during the growth (dissolution) of graphene. DFT calculations show that Pd work function can change due to the formation of metastable carbides and precipitation of C adatoms on the surface. Based upon our results, we suggest that graphene layers grow out of C atoms intercalated at the graphene-Pd interfaces.