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) - (Rt.3xRt.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: "Self-organization
of S adatoms on Au(111): Rt3R30 rows at low coverage"
was published July 6th, 2015 by Journal of Chemical
New publication: "Reconstruction
of steps on the Cu(111) surface induced by sulfur"
was published May 21st, 2015 by Journal of Chemical
Congratulations to Holly Walen for winning a 2015
Teaching Excellence Award from the Chemistry Department at Iowa State!
New publication: "Preface:
special topic on supramolecular self-assembly at surfaces" was published March 14th, 2015 by The
Journal of Chemical Physics.
New publication: "Cu2S3
complex on Cu(111) as a candidate for mass transport enhancement" was published January 22nd, 2015 by
Physical Review B.
New publication: "The
(111) Surface of NaAu2: Structure, Composition, and
Stability" was published
December 17th, 2014 by Inorganic Chemistry.
New publication: "Determining
whether metals nucleate homogeneously on graphite: A case study with
copper" was published
November 5th, 2014 by Physical Review B.
Welcome to our newest group members, graduate students Ann
Lii and Peter Spurgeon who joined Nov. 2014!
New publication: "Transition
metals on the (0001) surface of graphite: Fundamental aspects of
adsorption, diffusion, and morphology"
was published September 2nd, 2014 by Progress in Surface
Congratulations to David Appy for successfully
defending his Ph.D.! Thesis title: "Nucleation and growth of metals on
carbon surfaces". He will begin a Lecturer position at the end of
August for the Department of Chemistry at Iowa State University.
The Thiel group members are so very proud to congratulate Prof.
Thiel for being named the 2014 winner of the AVS Medard W.
Welch Award for "seminal contributions to the understanding of
quasicrystalline surfaces and thin-film nucleation and growth"! Please
refer to this news
release from the Ames Laboratory.
New publication: "Search
for the Structure of a Sulfur-Induced Reconstruction on Cu(111)"
was published August 7th, 2014 by The Journal of Physical
Congratulations to Emma Kwolek for winning a 2014
Teaching Excellence Award, and to Holly Walen for
winning the Dr. Ching Ching Chiu Fellowship for Women Doctoral
Chemistry Students! Both awards are from the Department of Chemistry
at Iowa State.
New publication: "Structure
of the clean Gd5Ge4(010) surface" was
published October 28th, 2013 by Journal of Physics Condensed
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 Review B.
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).