My current research interests cover a wide range of topics, some of which are relatively basic, such as Direct Methods, Surface Structures, and Density Functional Theory and Flexoelectricity, while other, such as Hip Replacements, Catalysis, Corrosion and Tribology, have a stronger eye on applications; see the links below the Research tab above for more details. Different from many research groups, we try more to focus on the science than any specific set of tools or techniques, an old-fashioned generalist approach. Much of the fundamental work involves combining cutting-edge variants of electron microscopy in a unique combination of an electron microscope and surface science system so we can combine more standard surface science probes, such as XPS or Auger, and chambers where samples are grown, all within one unique UHV system. Current projects include:
At the current moment it is very hard to predict the structure of oxide surfaces; this is an important problem because these are very important in a large number of different areas, ranging from catalysis through new types of oxide devices to corrosion. We are exploiting both our direct methods approach as well as careful electron microscopy to understand the atomic scale structures.
How heteroepitaxy occurs on strontium titanate
Cook, S., K. Letchworth-Weaver, I.C. Tung, T.K. Andersen, H. Hong, L.D. Marks, and D.D. Fong
Sci Adv, 2019. 5(4), eaav0764.
Electronic structure of lanthanide scandates
Mizzi, C.A., P. Koirala, and L.D. Marks
Physical Review Materials, 2018. 2(2), 025001
Pauling's rules for oxide surfaces
Andersen, T.K., D.D. Fong, and L.D. Marks
Surface Science Reports, 2018. 73(5), 213-232.
Transition from Order to Configurational Disorder for Surface Reconstructions on SrTiO3(111)
Marks, L.D., A.N. Chiaramonti, S.U. Rahman, and M.R. Castell
Phys Rev Lett, 2015. 114(22), 226101.
Friction is a pervasive problem, by some estimates consuming about 5% of the GDP of the economies of the developed world, and a recent analysis has indicated that about one third of the fuel energy in automobiles goes to overcoming frictional losses. While the importance of minimizing friction can be traced back at least as far as the tomb of Tehuti-Hetep, circa 1880 B.C, where a man can be seen pouring a lubricant to assist in moving a statue, there are still many unknowns in the field of tribology that encompasses friction as well as other critical processes, such as wear and lubrication. My interests lie in understanding the materials science of sliding at the nanoscale using both in-situ experimentation as well as theory.
In situ observations of graphitic staples in crumpled graphene
Lin, A.Y.W., X.X. Yu, A. Dato, G. Krauss, and L.D. Marks
Carbon, 2018. 132, 760-765
In situ single asperity wear at the nanometre scale
Liao, Y. and L.D. Marks
International Materials Reviews, 2017. 62(2), 99-115
Graphitic Carbon Films Across Systems
Hoffman, E.E. and L.D. Marks
Tribology Letters, 2016. 63(3), 32.
Soft Interface Fracture Transfer in Nanoscale MoS2
Hoffman, E.E. and L.D. Marks
Tribology Letters, 2016. 64(1), 16.
Nanoparticles: Plasmonics, Catalysis, and Fundamentals
My group has an active program in nanoparticles, ranging from their use in plasmonics and as catalysts to the fundamentals of their growth, thermodynamics and kinetics.
Kinetic Growth Regimes of Hydrothermally Synthesized Potassium Tantalate Nanoparticles
T. Ly, J. Wen, and L.D. Marks
Nano Lett, 2018. 18(8), 5186-5191.
Nanoparticle shape, thermodynamics and kinetics
L.D. Marks and L. Peng
J Phys Condens Matter, 2016. 28(5), 053001.
Identification of active sites in CO oxidation and water-gas shift over supported Pt catalysts
K. Ding, A. Gulec, A.M. Johnson, N.M. Schweitzer, G.D. Stucky, L.D. Marks and P.C. Stair
Plasmon Length: A Universal Parameter to Describe Size Effects in Gold Nanoparticles
E. Ringe, M.R. Langille, K. Sohn, J. Zhang, J.X. Huang, C.A. Mirkin, R.P. Van Duyne and L.D. Marks
Journal of Physical Chemistry Letters, 2012. 3(11): p. 1479-1483.
If every human vanished tomorrow, in a century or so the majority of our current technology would have vanished, due to corrosion of metals. Indeed, if we were not able to control corrosion our current civilization would look very different. It is really important to understand what is taking place at the atomic scale, and link this via experiment and theory to the macroscale.
New Insights on the Role of Chloride During the Onset of Local Corrosion: TEM, APT, Surface Energy, and Morphological Instability
Yu, X.X., A. Gulec, K.L. Cwalina, J.R. Scully, and L.D. Marks
Corrosion, 2019. 75(6), 616-627.
Nonequilibrium Solute Capture in Passivating Oxide Films.
Yu, X.X., A. Gulec, Q. Sherman, K.L. Cwalina, J.R. Scully, J.H. Perepezko, P.W. Voorhees, and L.D. Marks
Phys Rev Lett, 2018. 121(14), 145701.
Competitive Chloride Chemisorption Disrupts Hydrogen Bonding Networks: DFT, Crystallography, Thermodynamics, and Morphological Consequences
Corrosion, 2018. 74(3), 295-311.
Early Stage of Oxidation of Mo3Si by In Situ Environmental Transmission Electron Microscopy
Gulec, A., X.X. Yu, M. Taylor, A. Yoon, J.M. Zuo, J.H. Perepezko, and L.D. Marks
Corrosion, 2018. 74(3), 288-294.
Density Functional Theory
My group extensively uses Density Functional Theory (DFT) calculations to understand surface structures. In addition, I have an interest in the development of algorithms and methodologies to calculate properties faster and more accurately, and do much of the algorithm development and coding myself in my "spare time".
An Augmented Plane Wave + Local Orbitals Program for Calculating Crystal Properties
Blaha, P., K. Schwarz, G.K.H. Madsen, D. Kvasnicka, J. Luitz, R. Laskowsji, F. Tran, and L.D. Marks
2018: Techn. Universitat Wien, Austria.
Fixed-Point Optimization of Atoms and Density in DFT
L. D. Marks
Journal of Chemical Theory and Computation 9 (2013) 2786.
Robust mixing for ab initio quantum mechanical calculations
L.D. Marks and D.R. Luke, Physical Review B 78(7): p. 075114-12, 2008
(A gentler preprint)
Force calculation for orbital-dependent potentials with FP-(L)APW + lo basis sets
F. Tran, J. Kunes, P. Novak, P. Blaha, L.D. Marks, and K. Schwarz
Computer Physics Communications 179: p. 784-790, 2008
Prosthetic implantation is one of the most successful treatments for patients with severe arthritis or rheumatism; it is the difference between a wheelchair and a normal life. As of 2003, more than 200,000 total hip replacement operations were performed annually in the US, and this number is expected to reach 572,000 by 2030. The bearing surfaces of current artificial hip replacements on the market are usually made out of ultra-high-molecular-weight polyethylene (UHMWPE), cobalt-chromium-molybdenum (CoCrMo) alloys, ceramics (alumina) or ceramicized metals (e.g. oxygen diffusion-hardened ZrNb alloy). Unfortunately these materials are not perfect, and there are numerous problems. We are investigating the fundamentals of the metallurgy, tribology, corrosion as well as exploring some of the biological issues, in collaboration with scientists and physicians at Rush Orthopedics and elsewhere.
The effect of contact load on CoCrMo wear and the formation and retention of tribofilms
M.A. Wimmer, M.P. Laurent, M.T. Mathew, C. Nagelli, Y. Liao, L.D. Marks, J.J. Jacobs and A. Fischer
Wear, 2015. 332–333(0): p. 643-649
Intergranular pitting corrosion of CoCrMo biomedical implant alloy
Panigrahi, P., Y. Liao, M. Mathew, M.A. Wimmer, J.J. Jacobs, and L.D. Marks
Journal of Biomedical Research, 2013, 102B, 850-859
CoCrMo metal-on-metal hip replacements.
Y. Liao, E. Hoffman, M.A. Wimmer, A. Fischer, J.J. Jacobs, and L.D. Marks
Physical Chemistry and Chemical Physics. , 15 (2013) 746.
Graphitic Tribological Layers in Metal-on-Metal Hip Replacements (Supporting Info)
Y. Liao, R. Pourzal, M. A. Wimmer, J. J. Jacobs, A. Fischer and L. D. Marks
Science 334 (2011) 1687