Research Images
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)
165eV at 120 K
More images with descriptions
About Us
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.
News
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
this award.
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
special issue.
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.
Pat and her group are very, very happy to congratulate Danny
Shechtman on receiving the 2011 Nobel Prize in
Chemistry, for his discovery of quasicrystals!!!! For more
information, please vist the Nobel
Prize site and read the ISU
press release.
New publication: "Far-From-Equilibrium
Film Growth on Alloy Surfaces: Ni and Al on NiAl(110)" was
published Sept. 27, 2011 by Physical Review B.
Publication update: "Nucleation
and Growth of Ag Islands on the (?3x?3)R30° Phase of Ag on
Si(111)" was published July 6, 2011 by Journal of Physics:
Condensed Matter.
Publication update: "Weak
Bonding of Zn in an Al-Based Approximant, Based on Surface
Measurements" was published July 2011 by Philisophical
Magazine in a special issue: Proceedings of the Eleventh
International Conference on Quasicrystals: 13-18 June 2010, Sapporo.
New publication: "Nucleation
and Growth of Ag Islands on the (?3x?3)R30° phase of Ag on
Si(111)" was published online June 6, 2011 by Journal of
Physics: Condensed Matter.
Welcome to our newest group member, Assistant Scientist Mark
Wallingford who joined Apr. 2011.
Publication update: "Sulfur
Controls Nucleation of Ag Islands on Ag(111)" was published Feb.
2011 in Topics in Catalysis.
Publication update: "Nanodomains
due to Phason Defects at a Quasicrystal Surface" was published
Feb. 16, 2011 in Physical Review Letters.
Publication update: "Adsorption
of Sulfur on Ag(100)" was published Feb. 3, 2011 in Suface
Science.
New publication: "Sulfur
Controls Nucleation of Ag Islands on Ag(111)" was published
online Jan. 27, 2011 by Topics in Catalysis.