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Thin graphite overlayers: Graphene and alkali metal intercalation

Algdal, J.; Thiagarajan, Balasubramanian LU ; Breitholtz, M.; Kihlgren, T. and Wallden, L. (2007) In Surface Science 601(4). p.1167-1175
Abstract
Using LEED and angle resolved photoemission for characterisation we have prepared graphite overlayers with down to monolayer thickness by heating SiC crystals and monitored alkali metal intercalation for the multilayer films. The valence band structure of the monolayer is similar to that calculated for graphene though downshifted by around 0.8 eV and with a small gap at the zone corner. The shift suggests that the transport properties, which are of much present interest, are similar to that of a biased graphene sample. Upon alkali metal deposition the 3D character of the pi states is lost and the resulting band structure becomes graphene like. A comparison with data obtained for ex situ prepared intercalation compounds indicates that the... (More)
Using LEED and angle resolved photoemission for characterisation we have prepared graphite overlayers with down to monolayer thickness by heating SiC crystals and monitored alkali metal intercalation for the multilayer films. The valence band structure of the monolayer is similar to that calculated for graphene though downshifted by around 0.8 eV and with a small gap at the zone corner. The shift suggests that the transport properties, which are of much present interest, are similar to that of a biased graphene sample. Upon alkali metal deposition the 3D character of the pi states is lost and the resulting band structure becomes graphene like. A comparison with data obtained for ex situ prepared intercalation compounds indicates that the graphite film has converted to the stage I compounds C8K or CgRb. Advantages with the present preparation method is that the graphite film can be recovered by desorbing small amounts of alkali metal and that the progress of compound formation can be monitored. The energy shifts measured after different deposits indicate that saturation is reached in three steps. Our interpretation is that in the first the alkali atoms are dispersed while the final steps are characterized by the formation of first one and then a second (2 x 2) ordered alkali metal layer adjacent to the uppermost carbon layer. (c) Elsevier B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
silicon carbide, graphene, intercalation, alkali metal, angle resolved photoemission, graphite
in
Surface Science
volume
601
issue
4
pages
1167 - 1175
publisher
Elsevier
external identifiers
  • wos:000245155800040
  • scopus:33846807819
ISSN
0039-6028
DOI
10.1016/j.susc.2006.12.039
language
English
LU publication?
yes
id
8b86c7b2-80ae-4294-bce4-4456333c5e0d (old id 669522)
date added to LUP
2007-12-04 17:54:13
date last changed
2017-08-13 04:14:48
@article{8b86c7b2-80ae-4294-bce4-4456333c5e0d,
  abstract     = {Using LEED and angle resolved photoemission for characterisation we have prepared graphite overlayers with down to monolayer thickness by heating SiC crystals and monitored alkali metal intercalation for the multilayer films. The valence band structure of the monolayer is similar to that calculated for graphene though downshifted by around 0.8 eV and with a small gap at the zone corner. The shift suggests that the transport properties, which are of much present interest, are similar to that of a biased graphene sample. Upon alkali metal deposition the 3D character of the pi states is lost and the resulting band structure becomes graphene like. A comparison with data obtained for ex situ prepared intercalation compounds indicates that the graphite film has converted to the stage I compounds C8K or CgRb. Advantages with the present preparation method is that the graphite film can be recovered by desorbing small amounts of alkali metal and that the progress of compound formation can be monitored. The energy shifts measured after different deposits indicate that saturation is reached in three steps. Our interpretation is that in the first the alkali atoms are dispersed while the final steps are characterized by the formation of first one and then a second (2 x 2) ordered alkali metal layer adjacent to the uppermost carbon layer. (c) Elsevier B.V. All rights reserved.},
  author       = {Algdal, J. and Thiagarajan, Balasubramanian and Breitholtz, M. and Kihlgren, T. and Wallden, L.},
  issn         = {0039-6028},
  keyword      = {silicon carbide,graphene,intercalation,alkali metal,angle resolved photoemission,graphite},
  language     = {eng},
  number       = {4},
  pages        = {1167--1175},
  publisher    = {Elsevier},
  series       = {Surface Science},
  title        = {Thin graphite overlayers: Graphene and alkali metal intercalation},
  url          = {http://dx.doi.org/10.1016/j.susc.2006.12.039},
  volume       = {601},
  year         = {2007},
}