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
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 ofo 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.