Current frontiers in the rational design of nano-scale-ordered functional materials involve progress in both the synthesis of â€œbuilding blocksâ€ from molecular precursors (i.e., â€œbottom-upâ€ methods) and the use of these building blocks to create larger, more complex structures. For devising and improving such materials the conventional methods of trial and error are insufficient and a fundamental understanding of materials` structure is required. It is unfortunate that at present determination of atomic structure of nano-materials is still not a trivial task. Because of extremely small size of nano-crystals, the conventional X-ray diffraction technique cannot be used for solving their atomic structure. Only electron crystallography has a potential and the power to do this. Therefore, over the past three decades the technique of electron crystallography has become increasingly important. Electron crystallography is mainly based on a combination of electron diffraction analysis with electron imaging performed in transmission electron microscope (TEM). These methods allow full solution of atomic structure of unknown materials and characterization of structural imperfections. Both applications will be covered in current lecture. First, investigation of atomic structure of complex alluminides using electron diffraction tomography will be presented; then, study of antiphase boundaries in AlCoCrFeNi high entropy alloy will be shown.
2015-present Associate Professor, Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, Israel. 2015-2016 Guest researcher, Materials Science and Engineering Division, National Institute of Standards, Gaithersburg, MD, USA 2009-2015 Senior lecturer, Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, Israel. 2006-2007 Postdoctoral researcher, employed as research assistant. Department of Physics, University of Bristol, Bristol, UK. 2016 Excellence in teaching award, Ben Gurion University of the Negev. 2012 Krill prize for excellence in scientific research (provided by Wolf foundation). 2003 Wolf prize for excellence in doctoral research. 2001 Lev Margulis prize for excellent study in the field of electron microscopy. Prize is awarded by Israel Society for Microscopy.
Multifunctional borate crystals have gained substantial interest in several fields, such as nonlinear optics, laser engineering, ferromagnetic, phosphors and so on. Here, key results on crystal growth and characterization of rare earth borates RM3(BO3)4 (R=Y,Pr,Nd,Sm-Lu; M=Al, Cr) and RMgB5O10 (R=Y,La,Gd) are presented. This presentation is devoted to selected works related to these materials performed in Crystallography and Crystal Growth Laboratory at Lomonosov Moscow State University during last several decades, but mostly unpublished. All solids were obtained from fluxed melts based on K2Mo3O10 solvent using both spontaneous nucleation and by crystal growth on dipped seeds. Investigations towards creating novel optoelectronic devices using low-dimensional materials, namely epitaxial thin films, crystalline glass-composites, nano-ceramics, etc, has generated a drive for development of new methods in processing multi-functional micro- and nano-dimensional crystal materials.Therefore, new results on liquid-phase epitaxial growth of R:YAl3(BO3)4 (R=Er, Yb) are discussed. Since borate melts tend to glass formation, micro-crystallization processes in RAl3(BO3)4-B2O3 (R=Y,Gd) systems were also studied, to compare spectroscopic characteristics of Er andYb co-doped YAl3(BO3)4 and GdAl3(BO3)4single crystals and glass ceramic materials with similar chemical composition. Atdifferentstagesfromthe1990ï¿½sthroughnowadays,theseresearchworkswereperformedbytheauthorswithparticipationofstudentsandcolleagues.Wesincerelygratefulfor all ofthemforfruitfulcollaboration.Thisworkwassupported,inpart,bythegrants RFBR#18-29-12091 and RSCF #19-12-00235.
Nikolay I. Leonyukgraduated from Lomonosov Moscow State University (LMSU),completed and obtained his PhD from Geological Faculty of LMSU, then obtained DSc from Faculty of Chemistry, LMSU. He is a Professor and Scientific Supervisor of Crystallography and Crystal Growth Laboratory at LMSU. He is awarded Distinguished Professor of Moscow University. His research concerns crystal growth, crystallography and crystal chemistry of minerals and inorganic materials. He has published 9 books, 10 patents and over 700 papers in reputed journals.He has designed several long-term courses on crystal growth and he teachesthese coursesto Bachelor, Master and PhD students.
Quantum crystallography (QCr) aims at obtaining the complete quantum mechanics of a crystal given its X-ray scattering data. This is a revolution in crystallographic understanding of crystalline materials. The fundamental value of obtaining an electron density matrix that is N-representable is that it guarantees consistency with an underlying properly antisymmetrized wavefunction, a requirement of quantum mechanical validity. But mostly X-ray crystallography has progressed in an impressive way for decades based only upon the electron density obtained from a sum of spherical atoms model. Therefore, one may perhaps ask regarding N-representability â€œwhy bother?â€ Thus, it is the purpose of this article to answer such a question by forcefully describing the advantages opened by extracting from X-ray data the complete quantum crystallography.
Honors & Awards: Doctor of Humane Letters (Honoris causa) American Chemical Society, Westchester 2019 Distinguished Scientist Award Structural Chemistry Journal, Festschrift, October 2017, Volume 28, Issue 5, pp 1285â€“1291 ASEE Distinguished Visiting Professor at U.S. Naval Research Laboratory Hunter College President's Award for Excellence in Research U.S. Naval Research Laboratory's Berman Award for Outstanding Science Paper VISITING APPOINTMENTS: Harvard University, Brookhaven National Lab, Naval Research Lab, University of Bordeaux, University of London, IBM Watson Research Lab, University of North Carolina, University of New Orleans, Grumman Aerospace, Naval Surface Warfare Center. EDUCATION: Brookhaven National Lab, "Post-Doc." Georgetown University, Ph.D. Chemical Physics, Clarkson University, M.S. Chemical Physics, Lemoyne College, B.S. Physics Editorial Board: Structural Chemistry Journal (STUC) Science & Technology Editor CUNY-TV Book: Science & the Written Word, by Lou Massa, Oxford University Press, New York, 2011, ISBN: 9780199734320
It is known that in traditional power engineering hydrogen may be one of the firstprimary source of equipment damage. This problem has high actuality for both nuclear and thermonuclear power engineering owing to interaction of hydrogen with such nascent under neutron and ion irradiation nanoscale structures as radiation defects and grain-boundary segregants. The effects of neutron fluence and irradiation temperature on steel/hydrogen interactions (adsorption, desorption, diffusion, mechanical properties at different loading velocities, post-irradiation annealing) were studied. Experiments clearly reveal that the higher the neutron fluence and the lower the irradiation temperature, the more hydrogen-radiation defects occur, with corresponding effects on the RPV steel mechanical properties.It was determined that for steel specimens irradiated at relatively low (100-140Â°C) temperatures in sealed ampoules filled with argon hydrogen content was many times higher relatively initial content. It is necessary to look for enigmatic source of hydrogen especially because in frame of inspections numerous flows were detected in the forged rings of the reactor pressure vessels in the Belgian nuclear power plants Doel 3 and Tihange 2. The owner Electrabel claimed that flaws were â€œmost likelyâ€ hydrogen flakes. In this context radiation-stimulated diffusion of the impurity elements such as phosphorus, tin, antimony and so on with time may takes place and result in intergranular segregations on the former austenite grain boundaries. Hydrogen â€“ grain-boundary segregants interaction have to be taking into account as potential cause of the intergranular hydrogen embrittlement in reactor pressure vessel steel.
Education: Moscow Power Engineering Institute. Degree(s) or Diploma(s) obtained: Masterâ€™s Degree in Material Science â€“ 1970, Ph.D. â€“ 1974, D.Sc. -2005. Membership of professional bodies: member of Scientific Council of RAS on Radiation Damage Physics of Solids. Years within the firm: since 1974. Key qualification: responsible executor in Radiation Damage Physics of Solids. Professional experience record: since 1974 till now, Moscow, National Research Centre "Kurchatov Instituteâ€, Department: Reactor Materials and Technologies Institute.
The effects of temperature, thermomechanical loading, and heat treatment on the microstructural evolution, tensile strength, deformation behavior, and phase transformation were studied for the following low-cost metastable beta titanium alloys: Ti-12Cr (wt.%),Ti-12Cr-3Al (wt.%), Ti-12Cr-1Fe(wt.%),andTi-12Cr-1Fe-3Al (wt.%).Each of the alloys were conventionally processed using forging and rolling. In-situ and ex-situ tensile tests were performed at temperatures between 25Â°C to 500Â°C. The results indicated that the ultimate tensile strength (UTS) decreased with increasing temperatures up to 350Â°C. However, the UTS was 1435 MPa at 410Â°C, which was 150% higher than the room temperature UTS. Transmission electron microscopy was performed to investigate this phenomenon and phase transformations, from the beta to the omega phase and from the beta to the alpha phase, were responsible for this strengthening.Vickers hardness measurements confirmed this strengthening and a heat-treatment study was performed to understand the effect of heat treatment temperature and time on the strengthening. Transmission electron microscopy identified the fine nature of the precipitates in the beta-phase matrix, and the associated energy dispersive spectroscopy results noted the depletion of Cr in the precipitates.It is believed that the formation of the fine precipitates impeded the movement of dislocations, which resulted in the exceptionally high UTS. The temperature range of the phase transformations was investigated by dynamic mechanical analysis and compared with data from differential scanning calorimetry. Both temperature and thermomechanical loading have a significant influence on the phase transformations and resulting mechanical behavior and this will be discussed to highlight processing-microstructure-property relationships. Overall, a comprehensive mechanical property assessment of these alloys was performed using room temperature (RT) and 410Â°C tensile testing, RT and 410Â°C fatigue testing (R=0.1), 410Â°C tensile-creep testing, and hardness measurements. The as-processed microstructures were compared with samples heat-treated at 200Â°C, 300Â°C, and 410Â°C using X-ray diffraction and scanning electron microscopy. Overall the results indicate that such alloys exhibit potential for strength-drive applications and subtle changes in the alloy composition play a significant role in the thermomechanical processing window and resulting mechanical properties.
Boehlert received his B.S. degree in Agricultural and Biological Engineering at Cornell University. Boehlert earned M.S. and Ph.D degrees in Materials Science and Engineering at the University of Dayton, where he studied the physical metallurgy of advanced titanium alloys and their composites. While he was working on his Ph.D., he was employed as a contractor for UES, Inc. at Wright-Patterson Air Force Baseâ€™s Air Force Research Laboratory. There he worked on several projects within the Metal Matrix Composite Team. After leaving Dayton, Boehlert worked for two years as a postdoctoral fellow in the Mechanical Engineering Department of the Johns Hopkins University. There he worked on the physical metallurgy of TiAl intermetallic alloys. Boehlert then joined Los Alamos National Laboratory (LANL) as a postdoctoral research associate within the Nuclear Materials Technology Division, where he worked on the physical metallurgy of plutonium and cerium alloys. In September of 2001, Boehlert joined the New York State College of Ceramics at Alfred University as an assistant professor. Boehlert then joined the Department of Chemical Engineering and Materials Science in the College of Engineering at Michigan State University as an assistant professor in 2005. He was promoted to associate professor in 2007 and then to full professor in 2015. He served as a Visiting Professor at Tohoku University in Sendai, Japan from January to February of 2014 and spent a sabbatical at the MADRID Institute for Advanced Studies-Materials (IMDEA Materials Institute) from July 2010 through August 2011. He is a recipient of a National Science Foundation (NSF) CAREER Award and a Department of Energy (DOE) Presidential Early Career Award for Science and Engineering (PECASE). Boehlert has been an active member of ASM International and TMS since 1992. His research interests include materials engineering; materials sciences; metallurgy; electron backscatter diffraction; intermetallics electron microscopy; metal matrix composites; titanium alloys and composites; mechanical behavior. His research group is concentrating on understanding the deformation behavior of hexagonal close packed metals, in particular, titanium and magnesium alloys, under extreme environments.
Born at Jilin, Jilin province in 1969.Graduate from Jilin University, China, Dan Wang received the Bachelor’s degree from Jilin University in 1994. He entered a master’s degree program at his alma mater in the same year. He obtained his Ph.D. from Yamanashi University in Japan in 2001. He was awarded by Hundred Talent Program of the CAS, and served as professor of the Institute of Process Engineering, CAS in February 2004. And he earned the National Science Fund for Distinguished Young Scholars in 2013. He is a fellow of the Royal Society of Chemistry, and he sits on advisory boards for several international journals, such as Energy & Environmental Science, Advanced Science, Advanced Materials Interface. Research of his group is in the soft chemistry synthesis and application of inorganic functional materials including porous, layered and nano-sized materials. Emphases are placed on the development, design and application of the energy sources, catalyst and environment materials by self-assembly, surface modifying methods. Studies in the following fields are being performed: semiconductor metal oxide sensitive material, environmental friendly heat stabilizer for PVC, high efficient adsorbent for heavy metal ions, porous TiO2 films for photocatalysis, and so on.
Dongfeng Xue received his PhD from Changchun Institute of Applied Chemistry, Chinese Academy of Sciences in 1998. He worked as an Alexander von Humboldt research fellow in the Department of Physics, Universität Osnabrück (1999-2000); as a visiting researcher in the Department of Chemistry, University of Ottawa (2000-2001); as a Japan Society for the Promotion of Science (JSPS) postdoctoral fellow at National Institute for Materials Science (NIMS) in Tsukuba (2001-2003). He was appointed a full professor in 2001 in the School of Chemical Engineering, Dalian University of Technology.