Peter Moeck’s Scholarly Agenda and some of his recent accomplishments at Portland State University
October 1, 2009
Who I am and where I am coming from (metaphorically speaking)
I am by education a materials physicist and crystallographer. Materials physics may be considered as part of condensed-matter physics, which in essence explains the properties and behavior of macro-, meso-, and microscopic objects from their quantum mechanical foundations. While condensed-matter physics is mainly a fundamental science, materials physics has a much more applied focus. Crystallography is generally considered to be “part of the ‘science of the structure of matter’, the part associated with the atomic length scale” 1; see first footnote (*) for an alternative definition and a suggestion for its proper place in a modern science curriculum. Taken together, materials physics and crystallography are the scientific basis of the so-called double discipline of Materials Science & Engineering.
Since my graduation with an MSc in crystallography in 1983, I have worked mainly on semiconductors in physics or materials science departments (or physics institutes). Besides semiconductor crystal growth and processing, I mainly performed structural characterizations employing various modes of transmission electron microscopy, X-ray diffraction, X-ray topography at a synchrotron, and electron diffraction. Some of my best work was achieved by analyzing technologically relevant semiconductor growth or processing problems from a structural viewpoint by complementary methods and using my materials engineering background to understand the phenomenon/mechanism that caused the problem. This is what I like doing, want to continue doing, and have done well over the last 25 years in 3 different countries and at places as diverse as the University of Illinois at Chicago, the University of Oxford, Imperial College London, and the Humboldt University of Berlin.
Summary of prior and recent success as scientist and my place in the scientific enterprise
As a result of my scientific work and because I have established highly productive collaborations, I have 70 scientific journal articles, 10 patents, 2 book chapters, 89 conference talks and seminars, and 165 conference papers, posters, and abstracts to my credit. Two of the papers to which I contributed recently as coauthor were selected for re-publication in the Virtual Journal of Nanoscale Science and Technology. This is the highest honor a paper in my field can achieve. Since coming to Portland State University (September 16, 2002), I have published 41 peer-refereed papers, two book chapters, 75 non-refereed papers, presented 39 posters, applied for 4 patents (2 granted, 1 in press, 1 in the stage of applications), have presented 55 conference talks and seminars and edited one multi-author book.
Within the last 4 years, I was elected to memberships of the International Center for Diffraction Data2 and the Advisory Board of the Crystallography Open Database3. I also joined the Editorial Review Board of the “Journal of Nano Education”4, the Technical Review Committee of the Nano Science and Technology Institute (NSTI)5, and the Advisory Board of the Internet-based publisher “Scientific Journals International”6 (after having been invited to do so).
Within the last three years, I received the “Best Paper Award” from the organizers of the 2009 International Conference on Frontiers of Characterization & Metrology for Nanoelectronics, the (2008) “Outstanding Project Award” from the Northwest Academic Computing Consortium, and a “Best Poster Award” from the fall 2007 Meeting of the Materials Research Society.
With this kind of background, education, and track record, I am confident that my place within the scientific enterprise is right at the interface between materials physics and crystallography. It appears to me that the traditional boundaries between the scientific disciplines are disappearing with the emergence of nanoscience. In addition, new interdisciplinary developments typically start from niches at the interfaces between the traditional disciplines. My long-term goals are, therefore, to create, occupy, and expand my own scientific niches. I want to establish and expand my own scientific niches because I do seek intellectual challenges and have, as documented by my 9 patents and patent applications, mastered such challenges with originality. Within my scientific niches, I want to accomplish a seamless integration of my main activities: research, teaching, and community service. These goals also fit seamlessly into the PhD program in Applied Physics my department has been working to establish in recent years and is now formally proposing to the administrators and the State Board of Higher Education. Within our Applied Physics PhD program proposal, there are strong components in Materials Physics and interdisciplinary Nanoscience.
The five areas of my scientific activity
Prior to coming to Portland State University (PSU), my publications covered four topical areas in materials physics and crystallography: (i) electron microscopy, (ii) X-ray diffractometry and topography, (iii) compound (e.g. [Ga,In]Sb or GaN) semiconductor and (iv) element (e.g. Si or Sn) semiconductor growth, processing, and characterization by methods other than electron microscopy and X-ray scattering. As the recent entries in the attached lists of publications, patents, lectures, conference talks and seminars demonstrate, I am still active in each of these topical areas. This division into topical areas in my list of publications is due to having worked in a variety of fields at different times and places. As a commonality of my work in these different topical areas, I identified unsolved problems and found original solutions to them. This will be illustrated below using the example of my latest invention, structural fingerprinting in the transmission electron microscope from lattice-fringe and precession electron diffraction intensity data. Currently I am taking up electron crystallography of nanocrystals as a new research activity within the first topical area mentioned above.
Since my coming to PSU, (in other words: since becoming an educator in addition to being a researcher), I have established activities in a 5th area: materials science and engineering education (by publishing and presenting orally in this topical area at international conferences). Taking on this new area (of education and community service efforts) demonstrates my commitment to supporting PSU’s reputation for excellence in education and community service. The core of my activities in this area, i.e. promoting open-access crystallographic databases and computational services over the Internet worldwide, supports my long-term goals and research agenda directly. It, therefore, establishes the desired connection between my education, research, and service efforts that a mature Scholarly Agenda is supposed to represent.
Integrating community service into my scholarly agenda
Initially, as a kind of a community service project, I started the development of PSU’s “Open Access Crystallography web space”7 which associated open-access crystallographic databases. The initial work on developing the associated databases8 was supported externally by one grant from the Research Corporation and the three successive grants from the Northwest Academic Computing Consortium. I teamed up with the international project “Crystallography Open Database” (COD3). At our websites7 we provide three dimensional interactive visualizations of crystal structures at the atomic level and of crystal morphologies in addition to selected COD datasets and our own datasets on technologically relevant inorganic nanomaterials. Our site is, therefore, both a free materials science education resource and a service to those parts of the electron microscopy and condensed matter physics communities that work mainly with inorganic crystalline materials. We also created the first mirror of the COD for the Americas9. Note that a search for “open access crystallography” on google.com returns currently our project first out of 117,000 search results. (Besides being smaller than the COD, we are actually ahead of it as far as popularity measured by means of google.com is concerned. It is probably the interfaced 3D interactive visualizations and our computational bridge to structural fingerprinting of nanocrystals in the transmission electron microscope that make our site so popular.) Beginning January 1st 2008, we started counting the access to our crystallographic databases and reached more than 20,300 hits as of today.
As a result of my efforts since 2005, PSU now hosts a mainly inorganic subset (approximately 20,000 critically evaluated entries) of the COD’s more than 70,000 entries, a dedicated “Crystal Morphology Database**”, a dedicated “Nano-Crystallography Database”, and the “world’s first” open-access crystallography database in the “wikipedia format***”. The last of these databases was set up initially with an about 9,000 mineral subset of the COD and is freely expandable and editable by the general public. This is possible because our databases8 utilize the so-called CIF**** format. Our Nano-Crystallography Database, on the other hand, is a research database with registered users and its purpose will be discussed in more detail below.
The “CIF language” is the language of crystallographic computing because it allows for the transfer of crystallographic knowledge from computer programs that individual researchers wrote in the past and will write in the future, to a common pool of openly-accessible dictionaries10 that is rapidly growing and will in the end represent the world’s crystallographic knowledge in computer-readable and understandable form. Different scientific communities will develop their own dictionaries on the basis of the CIF concept. I as a crystallographer who works within the electron microscopy community would like to promote the development of a comprehensive CIF dictionary for that particular community. Open access to all of these dictionaries is guaranteed since the International Union of Crystallography (IUCr) legally owns the CIF concept (and the CIF dictionaries are freely distributed over the IUCr’s web pages). With crystallographic algorithms already in open access in the form of CIF dictionaries, one also needs to have CIF data in open access. This is exactly where the COD’s and on a smaller scale my group’s efforts in open-access database8 development come in. The International Advisory Board of the COD2 is mainly composed of well known X-ray and neutron crystallographers. Within this board, I represent the interest of the electron microscopy community.
From community service to helping address the “nanocrystal problem”
Crystalline nanomaterials are arguably the future of materials physics because they possess size- and morphology11-dependet properties. Any deeper understanding of these properties as it is required for applications and optimized reproducible syntheses must be based on the structure-size-morphology-property relationships of nanocrystals at the atomic level. This is where the so called “nanocrystal problem” 12 arises.
The nanocrystal problem has at least three compounding components, (i) many nanocrystals are “crystallographically challenged”12, i.e. are far from the ideal of a periodic structure that is sufficiently large so that surface effects can be safely neglected, (ii) the standard X-ray diffraction-based crystallographic techniques for both determining structures that are new to science and for recognizing structures that have already been determined (and have, thus, an entry in a database) frequently fail for nanocrystals, and (iii) there is no complete theoretical framework to describe nanocrystals. To me, this is a very interesting problem because its solution will lead to novel applications.
Solutions to the nanocrystal problem are anticipated by both (i) coordinated efforts of researchers using complementary methods on materials from the same batch and (ii) the open sharing of the accumulated experimental data in a “common computational global optimization framework.”12. This will allow theorists to make their unique contributions to the solution of the nanocrystal problem because theory can constrain structural models to be physically reasonable. Unexpected experimental results, on the other hand, help in the further development of new theories. I am working towards making PSU’s Nano-Crystallography Database part of the above envisioned “common computational global optimization framework”12.
Because I do want to make experimental contributions to the solution of the nanocrystal problem as well, I am working on the development of novel crystallographic characterization methods using transmission electron microscopy. These are my main research projects. They are funded by the Office of Naval Research (ONR) and the Oregon Nanoscience and Microtechnologies Institute (ONAMI) for the third year running. I am pursuing these projects both with external and PSU internal collaborators.
The first of these ONR/ONAMI-funded projects aims mainly at developing a novel method by which nanocrystals can be “fingerprinted” structurally in high-resolution transmission electron microscopes (HRTEM). Such a development is both necessary and timely because the traditional structural fingerprinting of crystalline powders by X-ray diffraction is inappropriate for nanocrystals. While the Bragg peaks of powder X-ray diffractograms become so broad for nanocrystals that they can no longer serve as “structure identifying markers”13, the small size of nanocrystals has just the opposite effect on the feasibility of our lattice-fringe fingerprinting strategy from HRTEM images14. This strategy has recently been enhanced by incorporating the extraction of the so-called structure factor phases (or structure factor amplitudes in cases of complementary electron precession diffraction data) for sufficiently small nanocrystals15.
The HRTEM image based lattice-fringe fingerprinting strategy has the advantage over diffraction pattern-based fingerprinting that the nanocrystal size distribution and morphology can be assessed simultaneously. This ability will be of importance for prospective industrial customers from the “nanocrystal powder-based industry”16. Nevertheless, the strategy can be complemented by two further strategies, precession electron diffraction of individual nanocrystals and of ensembles of nanocrystals. While the first of these complements is already described in our patent application15, structural fingerprinting of ensembles of nanocrystals is the topic of a new PSU invention disclosure17. These inventions have caught the attention of NanoMEGAS of Brussels, Belgium.
The collaboration with NanoMEGAS has lead to the establishment of my laboratory as the first demonstration site for precession electron diffraction systems (of this company) for the Americas. (We typically complement demonstrations of this hardware with demonstrations of a whole software suite for structural electron crystallography from the Calidris and AnaliTEX companies and plan to develop these activities into regular workshops.) Note that this is quite unique instrumentation since there is only one other such systems in all of the USA, at ExxonMobile Research & Engineering Co. Inc, Annandale, New Jersey. In Europe, on the other hand, there are already 39 precession electron diffraction systems. The collaboration with NanoMEGAS is mutually very beneficial because this company wants to commercialize structural fingerprinting of nanocrystals from electron precession data. The long term goal of my collaborations with local industry (FEI Company) is to establish at Portland State University the “world’s primary expertise site for structural fingerprinting of nanocrystals by transmission electron microscopical techniques”. I will also write THE BOOK on this subject during my sabbatical.
The second and third ONR/ONAMI-funded project both grew out of the realization that there is a real need for developing and employing electron crystallography***** in Oregon, within ONAMI and for the Pacific Northwest region. Analogous to the cases in which nanocrystals cannot be fingerprinted structurally by powder X-ray diffraction due to their nanometer size, their structure also cannot be elucidated by standard X-ray diffraction crystallography. The first ONR/ONAMI project supports the second and third because it makes sense to solve only nanocrystal structures that are truly new to science.
Collaborative projects in the Pacific Northwest Region
Within a large****** five year project that is sponsored by the National Science Foundation, I am currently collaborating (as co-PI) on the development of ferromagnetic semiconductors with researchers from the University of Washington at Seattle, the University of California at Davis, the Pacific Northwest National Laboratory, and the Lawrence Livermore National Laboratory. Two smaller projects that I am involved in as co-PI are sponsored by the Army Research Laboratory/ONAMI and present interesting challenges, i.e. electron crystallography of unknown nanomaterial structures.
Although I am interested in pursuing my own methodological developments, I also like to be a part of larger interdisciplinary research teams. As such I feel confident to work on the structural characterization of any kind of crystalline material. I had access (as PI) to sufficient research funds from the very first day onwards as a tenure-track assistant professor. This required a sustained effort in writing research proposals. As a result of this effort, I have gained the professionalism to maintain successful research programs in the future.
From science back to professional service
Similarly to the Pacific Northwest region and ONAMI, the nanomaterials science and engineering community of the whole country is poised to benefit from further developments in electron crystallography. Because the annual Microscopy & Microanalysis Meeting of the Microscopy Society of America18 will be held in Portland, Oregon, in August of 2010, Dr. Stavros Nicolopoulos, Founder and President of NanoMEGAS and I plan to organize an international summer school on recent developments in electron crystallography of nanocrystals as a satellite to that meeting. In preparation for that summer school, Dr. Nicolopoulos, Prof. Sven Hovmöller of the University of Stockholm, Prof. Phil Fraundorf of the University of Missouri at St. Louis, Prof. Sergei Rouvimov of PSU, and I organized the symposium “Electron Crystallography for Materials Research” at the 2009 Spring Meeting of the Materials Research Society in San Francisco. I also served as the lead editor of the joint proceedings “Electron Crystallography for Materials Research and Quantitative Characterization of Nanostructured Materials” (Volume 1184, Mater. Res. Soc. Symp.) from two symposia at this conference.
Note also that I received a kind acknowledgment for my contributions to this field by having been invited to contribute a review article for the special issue on "Structure of Nanocrystals" of the premier crystallographic journal Zeitschrift für Kristallographie, International journal for structural, physical, and chemical aspects of crystalline materials. This article is now published as part of the first open-access issue of this journal. Similarly, I am now working on a book chapter on the advantages of precession electron diffraction for structural fingerprinting in the transmission electron microscope.
Establishing materials physics and interdisciplinary materials science and engineering education at Portland State University
One of my aspirations since joining the Physics Department of Portland State University has been establishing materials physics and physical crystallography education and research at PSU. This aspiration is an outgrowth of my direct experiences at the other universities at which I worked and which have integrated materials physics and physical crystallography in the curricula that are taught in their Physics Departments. For example, the large Physics Department at the Humboldt University of Berlin, where I earned my Ph.D., had its own Crystallography/Materials Science Institute. The University of Illinois at Chicago, where I was a Research Assistant Professor before coming to PSU, also had its own Solid State/Materials Physics cluster with several experimentalists and theorists in their Physics Department. The Condensed Matter Physics sub-department at the University of Oxford also had a large physical crystallography group. (Prof. Robin J. Nicholas, head of the University of Oxford’s Condensed Matter Physics sub-department and one of my former collaborators, once wrote in a reference for me that my approach is “very physical” and that with these aspirations I am very well placed in a Physics Department.)
Similarly, but realistically on a smaller scale, I would like to establish a materials physics, physical crystallography, and nanocrystallography center of expertise for our comparatively small department and university. As part of this effort, I would like to provide materials physics and nano-(materials)-science & engineering education at different levels and I would like my prospective graduates to be recognized for their research at the interface between materials physics, physical crystallography, and nanoscience. Because crystallography* is by itself interdisciplinary, this would be a viable and valuable addition to the future nanoscience******* and engineering focus of interdisciplinary science and engineering programs at PSU.
I am very fortunate because several of my colleagues in Physics, Chemistry, Electrical and Computer Engineering, and Mechanical and Materials Engineering are also interested in developing advanced courses in nanoscience and nanoengineering. Over the last two summers, a total of 14 faculty members from these different departments volunteered their participation in Portland State University’s first interdisciplinary hands-on summer course on the “Fabrication and Characterization of Nanomaterials”. In support of this hands-on course and in addition with support of this interdisciplinary group of faculty members that is now called the “Portland Nanoscience and Nanotechnology Academy”, I developed a regular one quarter interdisciplinary course that is concerned with materials science and engineering at the nanometer length scale. My new “Introduction to Nano-(Materials) Science and Engineering” course, PH 481/581, focuses not only on the scientific foundations that are concerned with the nanometer length scale, but also covers recent engineering breakthroughs that resulted in early nanotechnology products. Nanofabrication and nanocharacterization already being reality receive significantly more coverage than prospective nano-devices. The size-dependence of electronic, magnetic, optical, mechanical, thermal, and chemical materials properties is covered at an introductory level. Recent developments in nano-bio-materials science and engineering are also discussed.
There are about fifteen PSU faculty members that are interested in developing interdisciplinary courses with an emphasis on the structure and properties of materials, be they minerals, metals, or semiconductors either in bulk, thin film, or nanocrystalline form. To me as a materials physicist and crystallographer, nanoscience and nanoengineering appear to be straightforward extensions of the interdisciplinary field of materials science and engineering into the nanometer and atomic realms. Nanoscience and nanotechnology are surely much wider and deeper, but contributing to nanoscience and nanoengineering education and research from a materials physics perspective will clearly benefit PSU and is, therefore, the core of my scholarly agenda.
International student and lecturer exchange in support of my scholarly agenda
To support both Portland State University’s efforts to develop nanoscience and nanoengineering educational opportunities for our science and engineering students and former PSU President Bernstine’s Internationalization Initiative, I also helped to establish a lecturer and student exchange program between PSU and the Technical University of Chemnitz (Germany). This opportunity is entirely financed by a German government agency and resulted from the personal initiatives of Profs. James Morris (PSU, Electrical and Computer Engineering), Michael Hietschold (Physics, Technical University of Chemnitz), and myself. Two of my graduate students spent one summer in Prof. Hietschold’s laboratory and used advanced electron microscopical equipment that is not available at Portland State University. I myself twice gave lecture series to graduate students on crystallography, electron microscopy, and nanoscience at the Technical University of Chemnitz. Several students from Chemnitz completed Master of Science or Engineering theses at PSU’s Physics Department and PSU’s Department of Electrical and Computer Engineering.
1 H. B. Bürgi, Zeitschrift für Kristallographie, International journal for structural, physical, and chemical aspects of crystalline materials 217 (2002) 288
2 http://www.icdd.com
3 http://crystallography.net; this open-access, Internet-based database is rapidly growing and currently contains more than 80,000 entries. After it was reviewed in the journal Science (Vol. 310 (2005) 597), it receives approximately 65,000 hits per month! At Portland State, we provide mirrors of this database at nanocrystallogrpaphy.org, and nanocrystallography.net (S. Gražulis, D. Chateigner, R. T. Downs, A. F. T. Yokochi, M. Quirós. L. Lutterotti, E. Manakova, J. Butkus, P. Moeck, A. Le Bail, Crystallography Open Database – an open access collection of crystal structures. J. Appl. Cryst. 42 (2009) 726-729, open access: http://journals.iucr.org/j/issues/2009/04/00/kk5039/kk5039.pdf).
4 http://www.aspbs.com/jne/
5 http://www.nsti.org/Nanotech2008
6 http://www.scientificjournals.org/index.htm
7 http://nanocrystallography.research.pdx.edu
8 http://nanocrystallography.research.pdx.edu/CIF-searchable
9 http://nanocrystallography.org
10 International Tables for Crystallography, Volume G, Definition and exchange of crystallographic data, S. Hall and B. McMahon, eds., Springer, Dordrecht, 2005
11 N. Tian, Z.-Y. Zhou, S.-G. Sun, Y. Ding, Z. L. Wang: Synthesis of Tetrahexahedral Platinum Nanocrystals with High-Index Facets and High Electro-Oxidation Activity, Science 316 (2007) 732-735
12 S. J. Billinge and M. G. Kanatzidis, Beyond crystallography: the study of disorder, nanocrystallinity and crystallographically challenged materials with pair distribution functions, Chem. Commun., April 7, 2004, 749-60; V. Petkov, K. K. Rangan, M. G. Kanatzidis, and S.J. L. Billinge, Structure of crystallographically challenged materials by profile analysis of atomic pair distribution functions: study of LiMoS2 and mesostructured MnGe4S10, Mat. Res. Soc. Symp. Proc. Vol. 678 (2001) EE1.5.1
13 N. Pinna, X-Ray diffraction from nanocrystals, Progr. Colloid. Polym. Sci. 130 (2005) 29-32
14 P. Fraundorf, W. Qin, P. Moeck, and E. Mandell, Making sense of nanocrystal lattice fringes, J. Appl. Phys. 98 (2005) 114308-1-114308-10; arXiv:cond-mat/0212281 v2; also re-published in Virtual Journal of Nanoscale Science and Technology Vol. 12 (2005) Issue 25
15 P. Moeck, Database supported nanocrystal structure identification by lattice-fringe fingerprinting with structure factor extraction, US Patent Application No. 11/800,422, Filing Date 05/03/2007, to be published November 6, 2008
16 A. Jillavenkatesa and J. F. Kelly, Nanopowder characterization: challenges and future directions, J. Nanopart. Res. 4 (2002) 463-468
17 P. Moeck, Method to structurally identify and characterize ensembles of nanocrystals from their precession electron diffraction ring and arc patterns, Portland State University Innovation & Industry Alliances Invention Disclosure, October 9, 2008.
18 http://www.msa.microscopy.org/
* Crystallography has also been defined recently as “… the science of condensed matter with emphasis on the atomic or molecular structure and its relation to physical and chemical properties”, P. Paufler, Zeitschrift für Kristallographie, International journal for structural, physical, and chemical aspects of crystalline materials 217 (2002) 357 (celebration issue of the 125th anniversary of the continued existence of this journal). In the same issue, H. B. Bürgi, states that “The structure and properties of crystals are such an important basis for physics, chemistry, materials sciences and even biology that they need to be integrated into the curriculum of every student in these fields. Whether such instruction is part of a program in physics, chemistry, biology or crystallography is of lesser importance, …”
** Our Crystal Morphology Database has a strong educational component and is topical because there is a renewed interest in the knowledge of crystal morphology that is driven by the demonstration that not only the size of a nanocrystal matters with respect to its properties, but also its morphology. (Catalytic properties of nanocrystals, for example, are controlled by crystal morphology10). Early mineralogists and crystallographers, on the other hand, developed a comprehensive and systematic crystal morphology description on the basis of the spatial arrangement of symmetry elements about 100 years ago. This framework can now be reused and expanded for nanocrystals, but needs to be popularized within the community of researchers and educators that deal with nanocrystals.
*** We uploaded mineral data to our “Wiki Crystallography Database” because there are many people interested in mineralogy and many active mineral collectors worldwide. Inspired by the success of the wikipedia, we hope that some of these people will contribute at least some of their knowledge to the world’s first website where everything about an inorganic crystal that is stable in the natural environment can be collected, searched, and openly accessed.
**** The CIF (for Crystallographic Information File) file format and the associated CIF dictionaries9 are the outcome of major efforts by the International Union of Crystallography (IUCr, which is a non-profit organization that represents the common interests of the world’s crystallographers and is also the main publisher of crystallographic reference books and journals). CIF is in essence a kind of “language” in which everything about a crystal can be communicated between human beings (who also read English), between human beings and computers, and between computers alone.
***** Solving unknown crystal structures on the basis of either electron diffraction intensities, or high-resolution phase-contrast transmission electron microscopical images, or a combination of both is commonly referred to as either electron crystallography or structural electron crystallography.
****** $2.500.000 over 5 years to be shared between one PI and 3 co-PIs. My share is approximately $80.000 per annum. This covers salary and fringe benefits for one postdoctoral researcher (approximately $50.000) that works for me at both the Lawrence Livermore National Laboratory and the University of California at Davis. Approximately $30,000 is directly subcontracted to me at PSU.
******* “Because disciplines are barely distinguishable at the nanoscale, the current boom in nano education offers us a unique opportunity to rebuild science education, literally from the bottom up, doing away with the classical disciplinary barriers that are rapidly becoming obsolete in our global research communities.” Robert P. H. Chang, Prof. of Materials Science, Northwestern University, General Secretary of the International Union of Materials Research Societies, and Principal Editor of the Journal of Materials Research, http://www.matsci.northwestern.edu/faculty /rphc.html.
