Michael Matthew John TREACY
Home Address: 140 West Courtney Lane, Phone: (480) 598-9021
Tempe, Arizona 85284-3911. email: email@example.com
Date & Place of Birth: 13th October 1954 Londonderry, N. Ireland
Cambridge University, St John’s College, U.K.
1980 Ph.D. (Cavendish Laboratory). Thesis Title: “Electron Microscopy of Palladium and Platinum Catalysts”. Supervisor, Dr. A. Howie.
1976 B.A. Hons. 2.1 Natural Sciences (Theoretical and Experimental Physics). Dissertation: “Dynamics of the Earth–Moon System”. Supervisor, Prof. A. H. Cook.
St. John’s College, Southsea, U.K.
1973 3 ‘A’ levels (three grade A passes), Distinctions in Physics and Mathematics.
1971 10 ‘O’ levels (six grade 1 passes).
6/2003–present Professor, Department of Physics
Arizona State University, AZ, USA
10/1990–11/2002 Senior Research Scientist
NEC Research Institute, Inc., Princeton, N.J., USA
9/1984–10/1990 Staff Physicist Exxon Research & Engineering Co, Corporate Research, N.J., USA
9/1982–8/1984 Senior Physicist
Exxon Chemical Company, Aromatics Technology Division, N.J., USA
4/1981–8/1982 Ingénieur (Grade II) Centre National d’Etudes des Télécommunications, Bagneux, Paris
1/1980–3/1981 IBM World Trade Post–Doctoral Position, IBM Thomas J. Watson Research Center, Yorktown Heights, N.Y., USA
• Co–Organizer of the Materials Research Society Symposium on “Microstructure and Properties of Catalysts” Editor Proceedings, Vol. No. 111. (12/1987)
• Meeting Chair 1991 Materials Research Society Fall meeting, with M. Yoo (Oak Ridge) & J. Phillips (Bell Labs).
• Treasurer, Editor, Executive Committee, 9th International Zeolite Conference, Montréal, 6/1992.
• Chairman of the Structure Commission of the International Zeolite Association, (7/2001 – present).
• Member of the Council of the International Zeolite Association (1998–2004).
• Member (retired) of the Steering Committee of the National Center for Electron Microscopy (1989–1994).
• Treasurer, Editor, Executive Committee, for the 12th International Zeolite Conference, Baltimore, 6/1998.
• Meeting Chair of Gordon Research Conference on “Zeolites and Layered Clays” 6/2002.
• Co-organizer of NSF Workshop on In-situ Microscopy of the nano-World, Tempe, AZ, 1/2006.
• Organizer of workshop on Design and Synthesis of New Materials, Santa Barbara, Aug 1-2, 2008.
• Personnel Committee for Department of Physics, Fall 2004 – spring 2006.
• Budget & Policy Committee for Department of Physics, fall 2006 – spring 2009.
• Colloquium Committee for Department of Physics, fall 2003 – present.
• Chair of the Physics Colloquium Committee, spring 2005 – fall 2008.
• Director of the Undergraduate Physics Program at Arizona State University, fall 2004 – present.
Wright Award 1974. Awarded by St. John’s College Cambridge, for academic excellence.
Best Biological Poster at the 1995 Microscopy Society of America conference (best out of 160).
Barrer Award 1990. Awarded triennially by the Royal Society of Chemistry to a young scientist under age 36, for distinguished work in the area of zeolites.
Donald W. Breck Award 1996. Awarded triennially by the International Zeolite Association for the most significant contribution to molecular sieve science and technology during that 3-year period – for elucidating fault structures in FAU/EMT zeolites.
Elected Fellow of the American Physical Society, Nov 2004, For the development of novel electron microscopy techniques and applications to advanced materials including catalysts, zeolites, carbon nanotubes and disordered structures.
Outstanding Teacher 2006–2007. Awarded by the Department of Physics at Arizona State University based on nominations by students and faculty.
Distinguished Teaching Award 2007–2008 in honor of Zebulon Pearce. Presented by the College of Liberal Arts and Sciences at Arizona State University based on nominations by students and faculty.
Nominee for Professor of the Year at ASU, spring 2009.
Leverhulme Professorship at the University of Oxford, Department of Materials, UK. Sabbatical leave, Aug 2009 – July 2010.
(1) June 1998, Invited lecture on “The Basics of Crystal Symmetry” at U. Illinois, Dept of Materials Science, given to graduate students.
(2) (2001-2004) “Reach For The Stars”. Astronomy coach for two students at Plainsboro, New Jersey, Middle School. They competed in the New Jersey qualifying tournament and the National Science Olympiad in 2002 (came 19th) and 2003 (came 10th). In 2004, the same team came first, although I did not coach them for that full year because I had moved to Arizona.
(3) Fall 2003. PHY132 at ASU. Taught laboratory class on Electricity & Magnetism. Acting T.A. to John Spence. (24 students)
(4) Fall 2003. PHY241. Substitute lecturer for Prof. D. J. Smith. 2 lectures. (About 70 students.)
(5) Spring 2004. PHY241 at ASU. Lecture course. 45ę50-minute lectures on Thermodynamics, Optics and Modern Physics. (72 students.)
(6) Guest Lecture (75 minutes) for course on Nanomaterials organized by Profs. T. Picraux and D. J. Smith. Lecture Title was “Synchrotron X-ray and Neutron Scattering”. (About 35 students)
(7) Fall 2004. PHY241 at ASU. Lecture course. 45ę50-minute lectures on Thermodynamics, Optics and Modern Physics. Did all of the quiz and exam grading myself. (78 students.)
(8) ASU Winter School on High Resolution Electron Microscopy. Lecture on Imaging Theory 1, and lab. classes (Jan 2005). (About 60 students)
(9) Spring 2005. PHY241 at ASU. Lecture course. 45ę50-minute lectures on Thermodynamics, Optics and Modern Physics. (71 students.)
(10) Fall 2005 PHY521 at ASU. Classical Mechanics. Taught at the graduate level, based on the Goldstein textbook. 26ę75-minute lectures. (17 graduate students)
(11) Fall 2005. PHY241 at ASU. Substitute lecturer for Prof. D. J. Smith. 4 lectures. (About 70 students.)
(12) ASU Winter School on High Resolution Electron Microscopy. Lecture on Imaging Theory 1, and lab. classes (Jan 2006). (About 45 students.)
(13) Spring 2006. PHY241 at ASU. Lecture course. 45ę50-minute lectures on Thermodynamics, Optics and Modern Physics. (68 students.)
(14) Spring 2006, PHY 541 (Surface Science) at ASU. Guest Lecture on Catalysis. (15 students.)
(15) Fall 2006. PHY521 at ASU. Classical Mechanics. Taught at the graduate level, based on the Goldstein textbook. 26ę75-minute lectures. (27 graduate students.)
(16) Fall 2006. PHY 310 at ASU. Stood in for Professor McCartney to give 3 lectures. (~30 students)
(17) Spring 2007. PHY241 at ASU. Lecture course. 45ę50-minute lectures on Thermodynamics, Optics and Modern Physics. (72 students.)
(18) Fall 2007. PHY521 at ASU. Classical and Continuum Mechanics. Taught at the graduate level, based on the Goldstein textbook. Additional material on fluids and chaos. 26ę75-minute lectures. (23 graduate students.)
(19) ASU Winter School on High Resolution Electron Microscopy. Two lectures on Imaging Theory 1 & II, and (Jan 2008). (About 70 students.)
(20) Spring 2008. PHY252 at ASU. Lecture and lab course. 26ę110-minute lectures on Waves, Fluids, Thermodynamics and Optics. 12ę110-minute lab classes. (42 students.)
(21) Fall 2008, PHY 521 at ASU. Classical and Continuum Mechanics. Taught at the graduate level, based on the Goldstein textbook. 26ę75-minute lectures. (23 graduate students.)
(22) Spring 2009, PHY 252 at ASU. Lecture and lab course. 26ę110-minute lectures on Waves, Fluids, Thermodynamics and Optics. 12ę110-minute lab classes. (33 students.)
(23) Spring 2009, PHY 311 at ASU. Stood in for Prof. Barry Ritchie for 1 lecture.
• NSF GOALI award DMR 00-74273, co-Principal Investigator with P. J. Keblinski at Rensselaer Polytechnic, supporting students R. Kishora-Dash and Juyin Cheng. “Structure of Amorphous Materials by Fluctuation Microscopy and Atomic-level Simulation”. 5/2004 – 5/2008, $240,000.
• Argonne National Laboratory (DOE) AWS-0046, “Fluctuation X-ray/Optical Microscopy Studies of disordered nano-scale and micro-scale assemblies”, $267,622.
• Petroleum Research Fund, 46779-AC10. $84,000, “Zeolite structure prediction, and the identification of useful synthetic targets”, 8/1/07 – 7/31/09.
• NSF MRI $3,277,750 “Acquisition of an aberration corrected high resolution analytical transmission electron microscope for advanced materials research”, co-PI with R. Carpenter, S. Mahajan, D. J. Smith, J. C. H. Spence 10/1/2008 – 9/30/2011.
• NSF CDI-type I $255,559 “Collaborative Research: CDI-type I: “Discovery and design of new microporous zeolites.”, PI with I. Rivin, Temple 9/1/2008 – 8/31/2011.
• Santa Barbara International Center for Materials Research (ICMR), $100,000, with Mike O’Keeffe (ASU), to run a Summer School and Workshop on Materials Design.
• UOP/Honeywell $30,000 unrestricted gift, to build a diffraction pattern database of hypothetical zeolites.
• Proposed, and demonstrated, the high-angle annular detector for STEM Z contrast
My Ph.D. work was on the development of advanced TEM-based techniques for the characterization of supported Pt and Pd catalysts. At that time, Crewe’s Z contrast technique seemed ideal for detecting high atomic number (Z) elements such as Pt, on low atomic number supports that are typical of supported catalysts. I demonstrated that diffraction produced strong contrast that overwhelmed the Z-contrast effect in crystals. In collaboration with supervisor A. Howie and L. M. Brown, I showed that upon increasing the annular detector inner collection angle, diffraction contrast could be suppressed. This work introduced the high-angle annular detector in Materials Science. Further, the Z-dependence of the signal improved to Z2 because atomic screening effects are diminished. (This seemingly simple experiment required time and some considerable ingenuity to overcome design limitations in the early STEM instruments.) In later work, I demonstrated single Pt atom sensitivity in zeolites, with the channels clearly imaged giving us an indication as to the likely location of Pt atoms in the framework. I also showed that high angle annular dark field intensities could be used to estimate sub-nanometer particle sizes reliably. The high-angle annular detector is now a standard tool in (S)TEM studies of materials.
• Identified a new deactivation mechanism in Pt/K-zeolite L aromatization catalysts
My STEM Z contrast studies of Pt particles in the one-dimensional channels of zeolite L revealed that Pt particles agglomerate slowly with reaction time. The particles remain sufficiently small so that over 90% of the Pt atoms reside on particle surfaces. However, double-blockages in the zeolite channels effectively entomb a significant channel volume, and the loss of active Pt can be severe. I proposed a length-loading criterion for maintaining activity. The criterion is simple: there should not be enough Pt per channel to form two or more significant blockages. This hypothesis was confirmed when zeolite L supports with shorter channel lengths, but identical Pt loading, were tested. For proprietary reasons this work (1982–1985), which represents the culmination of my early Z contrast work, was published only in 1999. I won the prestigious Barrer Award (awarded triennially by the British Zeolite Association) in 1990 for part of this work.
• Demonstrated the dominant role of elastic relaxation in TEM images of composition-modulated films
My work at CNET in Paris was on spinodal decomposition of InGaAsP semi-conductors, which are used as photodiodes in fiber-optic telecommunications. Electron microscopy revealed pronounced quasi-periodic image contrasts that were traditionally ascribed to local composition fluctuations. In collaboration with J. M. Gibson and A. Howie, I showed that the contrast is primarily due to the bending of lattice planes near surfaces, which is induced by relaxation of stresses arising from the modulation in unit cell dimensions as the composition changes. Such bending produces strong diffraction contrasts. I derived equations for the bending, which remain useful for studies of strain modulation in all types of modulated thin films, from superlattices to ferroelectrics. This work also showed how to convert TEM lattice spacings into a local composition, allowing for the relaxed tetragonal distortions and their dependence on thickness.
• Unraveled the structure of chiral zeolite beta
Synthetic zeolite beta was first reported by Mobil in the mid 1960s. Its structure remained a mystery for over 20 years. The presence of planar faults in the sub-micron sized crystallites made it essentially impossible to solve the structure by conventional structure-refining methods. Using TEM to extract structure projections and the symmetry elements, in collaboration with J. M. Newsam, I showed that the structure comprises intimately intergrown right- and left-handed variants of a chiral tetragonal framework. (It later transpired that J. B. Higgins at Mobil had solved the structure 3 years earlier by model-building, but had not been allowed to publish.) The zeolite beta structure is important because it is a 3-dimensional 12-ring framework, with helical channels running along the c-axis. Nobody has synthesized the pure right- or left-handed forms yet, but such a pure end-member structure may have applications in chiral separations. The methods I used, and the tools I created, in this work have been used by other researchers for structure determinations of other intergrown zeolite families.
• Invented recursion algorithm for computing diffraction from faulted crystals – DIFFaX
During the course of the zeolite beta work, I developed a recursion method of computing powder x-ray diffraction patterns in the presence of planar faults. This tool helped provide the crucial evidence supporting our model of zeolite beta. I am the primary author of the computer program DIFFaX, which has now become a standard tool for simulation of diffraction in planar-faulted crystals, and has been used widely by other researchers for over 20 years. I have used it successfully in many projects to identify fault patterns in layered crystal systems. The Fortran DIFFaX source code, with manual, is in the public domain.
• Characterization of stacking fault patterns in faujasitic zeolites using TEM and DIFFaX simulations
The tools I developed for studying zeolite beta where applied to studying the faulting distributions in the various faujasite-related synthetic zeolites, ranging from pure cubic FAU framework to the pure hexagonal EMT framework. Using TEM and DIFFaX, I showed that the faulting in these materials is correlated. Using the strain relaxation model, I showed that the strains associated with the stacking faults were reduced when faults were clustered. I won the prestigious Breck Award (awarded triennially by the International Zeolite Association) in 1996 for this work.
• Combinatorial computer method for enumerating zeolite frameworks
In collaboration with computer scientists K. Randall and S. Rao, I built a computer program to carry out a combinatorial search over every possible crystallographic graph in order to extract all of the 4-connected periodic zeolitic graphs. For one unique tetrahedral atom there are over 6,400 4-connected graphs, of which about 200 refine to regular tetrahedral topology. This work took over 10 years to bring to fruition, and discovered many new theoretical zeolite frameworks, and revealed some interesting idiosyncrasies in the International Tables for Crystallography. This work is collaboration with I. Rivin and Martin Foster. This is an active research area.
• Fluctuation Microscopy: A powerful TEM technique for revealing medium-range order in amorphous materials.
In collaboration with J. M. Gibson, we have shown that statistical analysis of the speckle observed in dark-field images of amorphous materials provides a measure of medium-range order. We have called this new analytical TEM technique Fluctuation Microscopy. We have used fluctuation microscopy to solve some long-standing problems in amorphous materials. We have shown that as-deposited amorphous germanium and silicon films contain paracrystalline regions. On annealing below the recrystallization temperature, Ge (but not Si) transforms to the lower-energy continuous random network. We have also shown that amorphous hydrogenated silicon (a-Si:H) undergoes a significant structural re-arrangement on light-soaking – an observation that may lead to an improved understanding of the Staebler-Wronski effect which currently limits the efficiency of a-Si:H solar cells. Fluctuation microscopy is now being used in several laboratories. This work remains active and has been extended to scanning x-ray microscopy of disordered nanomaterials (with I. McNulty and J. M. Gibson at Argonne), and also to scanning optical microscopy (student D. Kumar). This is an active research area.
• Schläfli cluster methods for modeling amorphous tetrahedral models.
Borrowing from my work on zeolite topologies, I have developed a simple topological tool for investigating medium-range order in models of amorphous tetrahedral semiconductors. Schläfli clusters are compact topological descriptors of the local connectivity around each atom. (It later emerged that they are similar to the earlier “local cluster” concept of L. W. Hobbs et al.) I have proposed that the diamond Schläfli cluster is the minimum atomic configuration that can be called “topologically cubic”. Searching for such clusters is a fast effective tool for detecting medium range order in models of amorphous semiconductors.
In collaboration with A. Krishnan, we made in-situ TEM observations of domain wall motion in thin single crystal ferroelectric materials under applied electric fields. I designed, and had built, a special TEM specimen holder that can heat, apply electric fields and shine light onto a sample. Our observations showed that domain walls do not move as rigid membranes. Instead, we proposed that domain walls move by allowing charged ripples to propagate along them. We developed a simple Landau-Ginsburg Free energy argument showing that ripples have a reduced barrier to switching. Ripples enable wall motion by a mechanism analogous to that for dislocation motion in crystal slip. We also showed that some domain walls are locked under certain electric field directions, representing an inherent contribution to ferroelectric fatigue and imprint.
• Developed an effective dynamical diffraction Bloch wave explanation for the anomalous transmission of light through thin hole arrays.
When light is shone on a thin metallic film, which has a periodic array of sub-optical wavelength diameter holes drilled through it, anomalously high intensities are transmitted at certain wavelengths. That is, more light gets through than would be expected from the projected hole area. The current popular explanation is that surface plasmons “guide” the light through the holes. I have developed an alternative dynamical diffraction Bloch wave theory that completely explains the anomalous transmission, and does so without resorting to special pleading about surface plasmons. The theory is fully general for 3-dimensional periodic gratings, and unlike the other theories, makes no simplifications or approximations to Maxwell’s equations.
• Exploited thermal vibrations to measure Young’s modulus of carbon nanotubes
Long carbon nanotubes that extend over holes in a TEM support film cannot be imaged clearly at their tips because of vibrations. The vibration amplitude at the tip can be several nanometers, and this blurring motion is normally a problem for high-resolution TEM studies. I realized that the vibrations are elastically relaxed phonons and represent heat motion. By measuring the r.m.s. vibration amplitude as a function of temperature, I estimated the Young’s modulus to be ~1.8 teraPascal, which makes carbon nanotubes the stiffest known material. Later, in collaboration with T. W. Ebbesen, A. Krishnan and E. DuJardin, we applied this method to single-walled nanotubes and obtained values of ~1.2 TPa, which we believe are closer to the correct value. In collaboration with P. Yianilos, I developed a hidden-parameter-inferencing technique to improve and quantify the accuracy of the method. This unique application of TEM attracted international attention, including highlights in Physics Today, C&E News, New Scientist, Bild der Wissenschaft etc…
• Designability of graphitic carbon cones.
In collaboration with Ebbesen, Krishnan and DuJardin, we described in the journal Nature a special carbon black sample that comprised a high density of graphitic disks and cones. Our TEM analysis confirmed that the five topologically-allowed conical forms all occur in this sample, but with a preponderance of the 60° cone-angle variety. I explained this distribution with a simple model of graphitization. I pointed out that there are many more ways to circumscribe carbon rings around the tip of a cone than there are ways to imbed the same rings in planar graphite. For topologically flexible seeds, graphitic cones are more “designable” than planar graphite. With an assumed seed distribution, the model explains the observed cone distribution – highlighting the role of entropy in the formation of curved graphitic structures.
• Primary author of the “Collection of Simulated XRD Powder Patterns For Zeolites”.
The Structure Commission of the International Zeolite Association maintains an up-to-date website describing the approved zeolite frameworks. Periodically, the Commission published updated handbooks describing zeolite frameworks and their diffraction patterns. I wrote a computer program that automates the production of the book “Collection of Simulated XRD Powder Patterns For Zeolites.” This was not a trivial task, but was an enjoyable, instructive and satisfying challenge. The program is due to be used next in 2012-2013 for the sixth edition.
• Mathematical tools for characterizing zeolite frameworks.
In part-collaboration with I. Rivin and Martin Foster, I have developed a number of public-domain computational tools for characterizing zeolite frameworks. TOTOPOL is used to explore zeolite structural details and topologies. It is my primary tool when examining new framework proposals to the IZA Structure Commission. DelaneysDonkey is a whimsically-named code that executes a Delaunay triangulation of zeolite frameworks to identify the largest included sphere and the largest freespheres in a framework. This gives a good idea of the porosity characteristics. I wrote both computer programs.
• Flexibility of zeolite frameworks.
In collaboration with Asel Sartbaeva, Stephen Wells and Mike Thorpe at ASU, we showed
that almost all of the known zeolites exhibit a
flexibility window when modeled as Ideal Zeolite
Frameworks. This important result provides a key test of hypothetical
frameworks; if they lack flexibility, the likelihood of them being realized in
nature is diminished. The composition of the framework is important, as the
presence of different-sized tetrahedra can promote or
diminish flexibility. An active research topic at present is the exploration of
the nullspace represented by the flexibility window,
with a view to computing the configurational entropy
of the framework. An open question at present is whether or not the entropic
density is a maximum when the framework density is minimum. Intuition says “yes,”
but we are exploring this using advanced computational tools
(collaboration with Vitaliy Kapko
and Colby Dawson.) This is an active research area.