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DEPARTMENT OF PHYSICS AND
ASTRONOMY
LINKS
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Research Overview
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Our research focuses on determining the electronic properties of
surfaces, ultrathin films and nanoscale structures using a number of
experimental techniques. Our work spans a wide range of materials
from simple metals to complex oxides. Current projects include
studying the electronic states of metallic quantum wells and
ultrathin oxide films; probing atom-specific electronic structure in
surface alloys; performing spin-dependent studies of
antiferromagnetic solids; and exploring energy and momentum
correlations between coincident pairs of photoemitted electrons. We
use a variety of techniques to perform these studies including
high-resolution photoemission, inverse photoemission using a newly
developed grating spectrograph, the novel technique of
Auger-photoelectron coincidence spectroscopy (APECS) with
synchrotron radiation (which was developed in our labs), and a
variety of scanning probe techniques including variable temperature
STM and AFM. Please click on the links at the left for more
information. |
Recent Highlight
Surface topography of
MOCVD-deposited epitaxial ZnO films
When doped with certain transition metal ions, ZnO is an attractive
candidate material for
a dilute magnetic semiconductor with a transition temperature above
room temperature. To use these materials in technological
applications, it is essential to characterize and understand the
film surface morphology on the atomic scale. Furthermore, the way in
which metal doping affects the surface properties can affect device
performance. The figure at the left shows a (100 x 100 nm) STM image
of the surface of a typical MOCVD grown ZnO epitaxial film. The film
is grown on r-sapphire with the (11-20) surface exposed. The surface
shows a pronounced rectangular structure with height difference that
show the presence of monatomic steps, as well as a number of bilayer
and trilayer steps. The surface exhibits terraces with widths
ranging from 50 to several hundred Angstroms.
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Recent
Publications
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Room temperature ferromagnetism in Mn ion
implanted epitaxial ZnO films
D.H.Hill, D.A. Arena,
R.A. Bartynski, P. Wu, G. Saraf, Y. Lu, Wielunski, R. Gateau, J.
Dvorak, A. Moodenbaugh, and Y.K. Yeo, Physica Status Solidi A,
203, 3836 (2006)
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Ferromagnetism in Fe-implanted a-plane ZnO
Films
D.P. Wu, G. Saraf, Y. Lu, D.H. Hill, D.A. Arena, R.A. Bartynski, L.
Wielunski, R. Gateau, J. Dvorak, A. Moodenbaugh, T. Siegrist, J.
A. Raley, and Yung Kee Yeo, Appl. Phys. Lett.89, 12508
(2006)
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The relation between crystalline phase,
electronic structure, and dielectric properties in high-k gate
stacks
S.
Sayan, M. Croft, N.C. Nguyen, T. Emge, J. Ehrstein, I. Levin, J.
Suehle, R.A. Bartynski, and E. Garfunkel, AIP Conf. Proc. 788,
92 (2005)
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Dichroic effects in Auger-photoelectron
coincidence spectroscopy of solids
R.
Gotter, F. Da Pieve. A. Ruocco, F. Offi, G. Stefani, R.A.
Bartynski, Phys. Rev. B. 72, 235409 (2005)
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Inverse Photoemission Spectroscopy from
Al(100)
J. F. Veyan, W. Ibanez, R.A.
Bartynski, P Vargas, and P. Haberle, Phys. Rev. B. 71,
155416 (2005)
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