The effects of beam precession on the Electron Energy Loss Spectroscopy (EELS) signal of the carbon K edge in a 2 monolayer graphene sheet are studied. In a previous work, we demonstrated the use of precession to compensate for the channeling-induced reduction of EELS signal when in zone axis. In the case of graphene, no enhancement of EELS signal is found in the usual experimental conditions, as graphene is not thick enough to present channeling effects. Interestingly, though it is found that precession makes it possible to increase the collection angle, and, thus, the overall signal, without a loss of signal-to-background ratio.

1.
D. A.
Muller
,
L. F.
Kourkoutis
,
M.
Murfitt
,
J. H.
Song
,
H. Y.
Hwang
,
J.
Silcox
,
N.
Dellby
, and
O. L.
Krivanek
, “
Atomic-scale chemical imaging of composition and bonding by aberration-corrected microscopy
,”
Science
319
(
5866
),
1073
1076
(
2008
).
2.
K.
Kimoto
,
T.
Asaka
,
T.
Nagai
,
M.
Saito
,
Y.
Matsui
, and
K.
Ishizuka
, “
Element-selective imaging of atomic columns in a crystal using STEM and EELS
,”
Nature
450
,
702
704
(
2007
).
3.
P. E.
Batson
,
N.
Dellby
, and
O. L.
Krivanek
, “
Sub-angstrom resolution using aberration corrected electron optics
,”
Nature
418
,
617
620
(
2002
).
4.
L. J.
Allen
,
S. D.
Findlay
,
A. R.
Lupini
,
M. P.
Oxley
, and
S. J.
Pennycook
, “
Atomic-resolution electron energy loss spectroscopy imaging in aberration corrected scanning transmission electron microscopy
,”
Phys. Rev. Lett.
91
,
105503
(
2003
).
5.
D.
Van Dyck
and
D. Op de
Beeck
, “
A simple intuitive theory for electron diffraction
,”
Ultramicroscopy
64
,
99
107
(
1996
).
6.
Y.
Wang
,
Q. Y.
Xu
,
X. L.
Du
,
Z. X.
Mei
,
Z. Q.
Zeng
,
Q. K.
Xue
, and
Z.
Zhang
, “
Determination of the polarity of ZnO thin film by electron energy-loss spectroscopy
,”
Phys. Lett. A
320
,
322
326
(
2004
).
7.
G.
Bertoni
and
Verbeek
, “
Accuracy and precision in model based EELS quantification
,”
Ultramicroscopy
108
,
782
790
(
2008
).
8.
R.
Vincent
and
P. A.
Midgley
, “
Double conical beam-rocking system for measurement of integrated electron diffraction intensities
,”
Ultramicroscopy
53
,
271
281
(
1994
).
9.
A.
Avilov
,
K.
Kuligin
,
S.
Nicolopoulos
,
M.
Nickolskiy
,
K.
Boulahya
,
J.
Portillo
,
G.
Lepeshov
,
B.
Sobolev
,
J. P.
Collette
,
N.
Martin
,
A. C.
Robins
, and
P.
Fischione
, “
Precession technique and electron diffractometry as new tools for crystal structure analysis and chemical bonding determination
,”
Ultramicroscopy
107
,
431
444
(
2007
).
10.
S.
Estradé
,
J.
Portillo
,
L.
Yedra
,
J. M.
Rebled
, and
F.
Peiró
, “
EELS signal enhancement by means of beam precession in the TEM
,”
Ultramicroscopy
116
,
135
137
(
2012
).
11.
A. K.
Geim
, “
Graphene: Status and prospects
,”
Science
19
,
1530
1534
(
2009
).
12.
M. H.
Gass
,
U.
Bangert
,
A. L.
Bleloch
,
P.
Wang
,
R. R.
Nair
, and
A. K.
Geim
, “
Free-standing graphene at atomic resolution
,”
Nat. Nanotechnol.
3
,
676
681
(
2008
).
13.
Z.
Liu
,
K.
Suenaga
,
P. J. F.
Harris
, and
S.
Iijima
, “
Open and closed edges of graphene layers
,”
Phys. Rev. Lett.
102
,
015501
(
2009
).
14.
K.
Suenaga
and
M.
Koshino
, “
Atom-by-atom spectroscopy at graphene edge
,”
Nature
468
,
1088
1090
(
2010
).
15.
H.
Varela-Rizo
,
I.
Rodriguez-Pastor
,
C.
Merino
, and
I.
Martin-Gullon
, “
Highly crystalline graphene oxide nano-platelets produced from helical-ribbon carbon nanofibers
,”
Carbon
48
,
3640
3643
(
2010
).
16.
R. F.
Egerton
,
EELS in the Electron Microscope
(
Plenum Press
,
1996
).
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