Northwestern Home Page   Professor Laurence Marks


Research is to see what everybody else has seen, and to think what nobody else has thought

Albert Szent-Györgi

Department of Materials Science and Engineering
Northwestern University
Evanston IL 60208, USA
Phone: (847) 491 3996
Fax: (847) 491 7820
Email L-marks at northwestern dot edu

Research Interests

My research interests cover a wide range of topic some of which are relatively basic such as Direct Methods, Surface Structures, and Density Functional Theory while others such as Hip Replacements, Environmental Catalysis, and Tribology have a stronger eye on applications; see the research page for more details. 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:

Oxide Surfaces

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 and corrosion. We are exploiting both our direct methods approach as well as careful electron microscopy to understand the atomic scale structures.

  1. A chemical approach to understanding oxide surfaces
    J. A. Enterkin, A. E. Becerra-Toledo, K. R. Poeppelmeier, and L. D. Marks
    Surface Science 606 (2012) 344
  2. Water adsorption on SrTiO3(001): I. Experimental and simulated STM
    A. E. Becerra-Toledo, M. R. Castell and L. D. Marks
    Surface Science 606 (2012) 762
  3. Water adsorption on SrTiO3(001): II. Water, water, everywhere
    A. E. Becerra-Toledo, J. A. Enterkin, D. M Kienzle and L. D. Marks
    Surface Science 606 (2012) 791
  4. c(4 × 2) and related structural units on the SrTiO3(001) surface: Scanning tunneling microscopy, density functional theory, and atomic structure
    A. E. Becerra-Toledo, M. S. J. Marshall, M. R. Castell and L. D. Marks
    The Journal of Chemical Physics 136 (2012) 214701
  5. Surface Transmission Electron Diffraction for SrTiO3 surfaces
    D. M Kienzle, L. D. Marks
    CrystEngComm 14 (2012) 7833.

Hip Replacments

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.

  1. 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.

  2. New insights into hard phases of CoCrMo metal-on-metal hip replacements
    Y. Liao, R. Pourzala, P. Stemmera, M. A. Wimmerc, J. J. Jacobsa, A. Fischerb, L. D. Marks
    Journal of the Mechanical Behavior of Biomedical Materials 12 (2012) 39
  3. Graphitic Tribological Layers in Metal-on-Metal Hip Replacements
    Y. Liao, R. Pourzal, M. A. Wimmer, J. J. Jacobs, A. Fischer and L. D. Marks
    Science 334 (2011) 1687
    , and Supporting Info

Nanotribology

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 moving a statue, there are still many unknowns in the field of tribology which 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.

  1. Graphitic Tribological Layers in Metal-on-Metal Hip Replacements
    Y. Liao, R. Pourzal, M. A. Wimmer, J. J. Jacobs, A. Fischer and L. D. Marks
    Science 334 (2011) 1687
    , and Supporting Info
  2. Quantification of sliding-induced phase transformation in N3FC diamond-like carbon films
    A. M'ndange-Pfupfu, O. Eryilmaz, A. Erdemir, and L.D. Marks
    Diamond and Related Materials 20 (2011) 1143
  3. Direct observation of tribological recrystallization
    Y. Liao, S.K. EswaraMoorthy and L.D. Marks
    Philosophical Magazine Letters 90 (2010) 219.
  4. In situ TEM studies of tribo-induced bonding modifications in near-frictionless carbon films
    A.P. Merkle, A. Erdemir, O.L. Eryilmaz, J.A. Johnson, L. D. Marks
    Carbon 48 (2010), 587.
  5. Modeling of Thermal-Assisted Dislocation Friction
    Y. Liao, L. D. Marks
    Tribology Letters 37 (2010) 283.
  6. A Dislocation-Based Analytical Model for the Nanoscale Processes of Shear and Plowing Friction
    A. M'ndange-Pfupfu and L.D. Marks
    Tribology Letters 39(2010) 163.

Nanoparticles: Plasmonics, Catalysis, Fuel Cells and Fundamentals

While nanoparticles have been a popular topic for the last decade, there is still much we do not understand particularly about how the shape matters for the properties both for plasmonic properties as well as catalysis and many other applications. My interests are to marry the materials science with the properties in a range of areas.
  1. 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.
  2. Oriented Catalytic Platinum Nanoparticles on High Surface Area Strontium Titanate Nanocubes
    J. Enterkin, K. R. Poeppelmeier and L. D. Marks
    Nano Letters 11 (2011) 993
  3. Pd-substituted (La,Sr)CrO3-delta;-Ce0.9Gd0.1O2-delta Solid Oxide Fuel Cell Anodes Exhibiting Regenerative Behavior
    D. M. Bierschenk, E. Potter-Nelson, C. Hoel, Y. Liao, L. D. Marks, K. R. Poeppelmeier and S. A. Barnett
    Journal of Power Sources 196 (2011) 3089
  4. Correlated Structure and Optical Property Studies of Plasmonic Nanoparticles
    A. I. Henry, J. M. Bingham, E. Ringe, L. D. Marks, G. C. Schatz and R. P. Van Duyne
    Journal of Physical Chemistry C 115 (2011) 9291
  5. Propane oxidation over Pt/SrTiO3 nanocuboids
    J. A. Enterkin, W. Setthapun, J. W. Elam, S. T. Christensen, F. A. Rabufetti, L. D. Marks, P. C. Stair, K. R. Poeppelmeier and C. L. Marshall
    ACS Catalysis 1 (2011) 629
  6. Wulff Construction for Alloy Nanoparticles
    E. Ringe, R. P. Van Duyne, and L.D. Marks
    Nano Letters 11 (2011) 3399
  7. Operational Inhomogeneities in La0.9Sr0.1Ga0.8Mg0.2O3-x Electrolytes and La0.8Sr0.2Cr0.82Ru0.18O3-xCe0.9Gd0.1O2-x Composite Anodes for Solid Oxide Fuel Cells
    Y. Liao, D. M. Bierschenk, S. A. Barnett and L. D. Marks
    Fuel Cells 11 (2011) 635

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”.

  1. A chemical approach to understanding oxide surfaces
    J. A. Enterkin, A. E. Becerra-Toledo, K. R. Poeppelmeier, and L. D. Marks
    Surface Science 606 (2012) 344
  2. Robust mixing for ab initio quantum mechanical calculations
    L.D. Marks and D.R. Luke, Physical Review B 78(7): p. 075114-12, 2008
    & for a gentler preprint see
  3. 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
  4. Enhancing structure relaxations for first-principles codes: an approximate Hessian approach
    J. Rondinelli, D. Bin, and L.D. Marks
    Computational Materials Science 40: p. 345-353, 2007