STM: Al-Pd-Mn quasicrystal, 15x15 nm2
Root-mean-square roughness, W, as a function of annealing
temperature, for various surfaces based on STM images.
Note: Al-Pd-Zn and Al-Cu-Co are quasicrystals.
STM: Ag on top of Ag/Si(111) - (?3x?3)R30° at 250 K
STM: Au islands on NiAl(110) at 300 K, 150x150 nm2
STM: S reconstruction of Ag(100) after heating to 300 K, 100x100 nm2
LEED: clean NiAl(110)
More images with descriptions
165eV at 120 K
We try to understand real problems in corrosion, lubrication,
heterogeneous catalysis and microelectronics (thin films) by creating
simple model surfaces and studying their chemistry on an atomic scale.
We then extrapolate this information back to the real system, where
such knowledge is often unobtainable, either because of a lack of
adequate experimental techniques or because of misleading extraneous
factors. In order to create a simple model of a surface chemical
process, we use single crystal surfaces with known morphology.
Ultrahigh vacuum provides the well-controlled chemical environment
necessary to study a reactive surface over a period of several hours.
We can deliberately expose the sample to a chosen gas in order to
change its surface composition and then characterize it.
There are three major projects currently underway in my group. These
projects have all been selected because of their importance to
fundamental and applied surface chemistry, and also because they are
relatively new and unexplored. These projects involve:
We primarily use scanning tunneling microscopy (STM) and low-energy
electron diffraction (LEED) in our studies. Examples are shown to the
left and on the linked pages
New publication: "Analytic
formulations for one-dimensional decay of rectangular homoepitaxial
islands during coarsening on anisotropic fcc (110)
surfaces" was published October 24th, 2013 by Physical
Congratulations to Dahai Shao for successfully
defending his Ph.D.! Thesis title: "Surface-Supported Ag Islands
Stabilized by a Quantum Size Effect: Their Interaction with Small
Molecules Relevant to Ethylene Epoxidation."
New publication: "Intermetallic
NaAu2 as a heterogeneous catalyst for low temperature CO
oxidation" was published June 11, 2013 by Journal of the
American Chemical Society.
New publication: "Growth
of fcc(111) Dy multi-height islands on 6H-SiC(0001) graphene"
was published May 15, 2013 by Journal of Physics: Condensed
New publication: "Anisotropic
coarsening: One-dimensional decay of Ag islands on Ag(110)"
was published April 17, 2013 by Physical Review B.
New publication: "Communication:
Structure, formation and equilibration of ensembles of Ag-S
complexes on an Ag surface" was published February 15, 2013 by Journal
of Chemical Physics.
New publication: "Surface
Characterization of Clean Gd5Ge4(010)" MRS
Proceedings 1517 (2013).
Welcome to our newest group member, graduate student Allison
White who joined Nov. 2012.
Congratulations to Chad Yuen for successfully
defending his Ph.D.! Defence title: "Surfaces of Intermetallics:
Quasicrystals and Beyond."
Congratulations to Selena Russell for successfully
defending her Ph.D.! Defence title: "Mass Transport and
Chalcogen-Silver Interactions on Silver Surfaces." She will begin a
postdoctoral position at the Army Research Laboratory in the
Electrochemistry Branch of the Sensors
and Electron Devices Directorate Nov. 2012.
New publication: "Effect
of Oxygen on the Stability of Ag Islands on Si(111)-(7x7)" will
be published December 2012 in Surface Science.
New publication: "Creating
nanoscale Ag patterns on the Si(111)-(?3x?3)R30°-Ag surface
via guided self-assembly" was published July 20, 2012 by Journal
of Vacuum Science and Technology B.
Welcome to our newest group member, graduate student Emma
Kwolek who joined May 2012.
Congratulations to Alex Belianinov for
successfully defending his Ph.D.! Defence title: "Ag on Si(111) From
Basic Science to Application." He will begin a postdoctoral position
at Oak Ridge National
Laboratory Oct. 2012.
Congratulations to Alex Belianinov for winning a
2012 Research Excellence Award from the Department of Chemistry.
Congratulations to David Appy and Dahai
Shao for winning 2012 Teaching Excellence Awards from the
Department of Chemistry. They join Chad Yuen and Selena
Russell in the ranks of current group members who have won
New publication: "Preferential
surface oxidation of Gd in Gd5Ge4" was
published Jan. 15, 2012 by Applied Surface Science.
New publication: "A
distinctive feature of the surface structure of quasicrystals:
intrinsic and extrinsic heterogeneity" was published Dec. 23,
2011 by Israel Journal of Chemistry in a Quasicrystals
Guest editorial: "Quasicrystals"
was published Dec. 23, 2011 by Israel Journal of Chemistry
in a Quasicrystals special issue.
Welcome to our newest group member, graduate student Holly
Walen who joined Nov. 2011.
New publication: "Destabilization
of Ag nanoislands on Ag(100) by adsorbed sulfur" was published
online Oct. 17, 2011 by The Journal of Chemical Physics.