BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Growth mechanisms and electronic properties of epitaxial graphene 
  - Dr Graham Creeth\, University College London
DTSTART:20140609T131500Z
DTEND:20140609T141500Z
UID:TALK52318@talks.cam.ac.uk
CONTACT:Teri Bartlett
DESCRIPTION:Epitaxial growth on SiC is a candidate for exploiting graphene
 ’s extraordinary properties in technological applications [1]. Growth is
  achieved by annealing at temperatures above 1200 ◦C\, causing Si to eva
 porate from the SiC preferentially to C\; the resulting carbon-rich surfac
 e forms a graphitic layer with the structural and electronic properties ex
 tremely sensitive to annealing conditions [2]. \n\nWe present electronic t
 ransport and low energy electron microscopy (LEEM) data for (000-1) 4H SiC
  samples annealed under UHV at various temperatures. The evolution of cohe
 rent electronic transport occurs for samples annealed at higher temperatur
 es\, as the size of individual graphene domains increases from tens of nm 
 to several microns. Using a two-stage annealing protocol\, we show that th
 e larger grain size is due to a coalescence mechanism\, as opposed to fast
 er propagation of single grains. \n\nFitting Magnetotransport (MR) data to
  weak localisation or weak anti-localisation models [3\, 4] yields electro
 n scattering rates for various processes\, while subtraction of the fits f
 rom the measured data allows less dominant contributions to magnetotranspo
 rt from electron-electron interations and mesoscopic phenomena to be disce
 rned. \n\nThis work was supported by the EPSRC and Intel Ireland.\n\nRefer
 ences \n1.	[1]  C. Berger\, Z. Song\, T. Li\, X. Li\, A.Y. Ogbazghi\, R. F
 eng\, Z. Dai\, A.N. Marchenkov\, E.H. Conrad\, P.N. First\, and W.A. deHee
 r. Ultrathin epitaxial graphite: 2D elec- tron gas properties and a route 
 toward graphene-based nanoelectronics. Journal of Physical Chemistry B\, 1
 08(52):19912–19916\, 2004. \n2.	[2]  Luxmi\, N. Srivastava\, Guowei He\,
  R. M. Feenstra\, and P. J. Fisher. Comparison of graphene formation on C-
 face and Si-face SiC {0001} surfaces. Phys. Rev. B\, 82(23):235406\, Dec 2
 010. \n3.	[3]  Xiaosong Wu\, Xuebin Li\, Zhimin Song\, Claire Berger\, and
  Walt A. de Heer. Weak antilocalization in epitaxial graphene: Evidence fo
 r chiral electrons. Phys. Rev. Lett.\, 98(13):136801\, 2007. \n4.	[4]  E. 
 McCann\, K. Kechedzhi\, Vladimir I. Fal’ko\, H. Suzuura\, T. Ando\, and 
 B. L. Altshuler. Weak-localization magnetoresistance and valley symmetry i
 n graphene. Phys. Rev. Lett.\, 97(14):146805\, 2006. \n
LOCATION:Mott Seminar Room\, Cavendish Laboratory\, Department of Physics
END:VEVENT
END:VCALENDAR