Tag: John & Virginia Towers Lecture Series

A New Model for the Critical Thickness of Metallic Amorphous Thin Films

Friday, September 18, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Jong K. Lee
Department of Materials Science and Engineering
Michigan Technological University

Abstract

A new model for the critical thickness of amorphous metallic thin films isproposed in which the surface free energy difference, Δγ, equals γCV +γCA – γAV, where γCV is the crystalline-vapor, γCA the crystallineamorphous, and γAV, the amorphous-vapor interface free energy. It ispredicated upon experimental evidence that non-epitaxial film growthdue to large atomic-size difference dictates one or two amorphousatomic layers in contact with the substrate phase. Consequently, themodel does not require hardly-accessible film-substrate interface freeenergies in predicting the critical thickness for amorphous-crystallinetransition.

Read more here.


Formation of Nano Metal Particles Under the Influence of Argon discharge Plasmas

Monday, August 10, 2009 2:30 – 3:30 pm
Room 607, M&M Building

Professor Chang-jun Liu
Tianjin University
China

Abstract

Highly dispersed noble metal nanoparticles can be produced in solution, ionic liquids or withinvarious porous materials at room temperature using glow discharge plasma reduction. Theprepared nanoparticles were characterized with UV-visible absorption spectra (UV-vis), X-rayphotoelectron spectroscopy (XPS), transmission electron microscopy (TEM) equipped with anenergy dispersion X-ray spectrometer (EDX), catalytic reactions and others. The nucleation andgrowth of nanoparticles under the influence of the plasma are closely related with the highenergy electrons generated by glow discharge plasma. Because of its simple, economical andextremely time efficient synthesis procedure, this facile and one-step method will be verypromising as an alternative route for the preparation of metal colloids and supportednanoparticles, which would be significant for both fundamental and applied researches.

Biography

Chang-jun Liu is a Professor at School of Chemical Engineering and Technology ofTianjin University. He obtained B.S degree in Chemical Engineering from Dalian Institute ofTechnology (1985), M.S. degree in Chemical Engineering from Dalian University of Technology(1988) and Ph.D. degree in Organic Chemical Technology from Tianjin University (1993).

Chang-jun Liu is the author of more than 120 scientific articles and editor of an ACS Book andguest editor of Catalysis Today and Green Chemistry. His academic services include Chairmanof the 10th International Conference on CO2 Utilization, Organizer of several Symposia in theNational Meeting of American Chemical Society and 2010 Program Chair of Fuel ChemistryDivision of American Chemical Society. His professional honors include the NSFC DistinguishedYoung Scholars (2002) and Chang Jiang Distinguished Professorship (2004). He has deliveredthe Specialized iNANO Lecture at Aarhus University of Denmark (2008), Seminar of School ofChemical Engineering and Materials Science of University of Oklahoma (2002), the MaterialsTechnology Center Seminar of Southern Illinois University (2005), Seminar at Pacific NorthwestNational Laboratory (2006) and the Surface Science & Catalysis Seminar at Lawrence BerkeleyNational Laboratory (2008).


Energy for Sustainability

Friday, April 17, 2009 3:00 – 4:00 pm
Room U113, M&M Building

Trung Van Nguyen
Program Director
CBET Division – Engineering Directorate
National Science Foundation
Arlington, VA

Abstract

Hydrocarbon-based fossil fuels are rapidly depleted. Use of coal-based fuels is expected toincrease leading to environmental concerns. To address these problems, more efficient use ofexisting resources and alternative sources will be needed. I will share some of my views andvision and discuss the potential solutions and challenges and the role of NSF and my Energy forSustainability Program at NSF in this area.

Biography

Trung Van Nguyen was elected to be the first Director for the Energy forSustainability program at NSF and started his position in June 2007.   Concurrently, he alsoholds the title of Professor of Chemical & Petroleum Engineering at the University of Kansas. Hehas a BS from North Carolina State University and MS and PhD from Texas A&M University, allin Chemical Engineering. Prior to joining the faculty at the University of Kansas, he was aPostdoctoral Fellow at Los Alamos National Lab, Senior Product & Process DevelopmentEngineer at Duracell, Associate Director of the Center for Electrochemical Engineering at TexasA&M University, and Member of Technical Staff at AT&T Bell Labs. He has 5 patents, over 75publications, given over 130 presentations, and received awards for research, teaching andservices. He is also a founder of two fuel cell start-up companies. His current research is ontransport and interfacial phenomena in fuel cells and batteries and mathematical modeling ofelectrochemical systems.


X-ray Micro CT for 3D Characterization, Analysis, and Simulation of Multiphase Systems

Friday, April 10, 2009 3:00 – 4:00 pm
Room 610, M&M Building

J.D. Miller
Chair and Ivor D. Thomas Distinguished Professor
Department of Metallurgical Engineering
College of Mines and Earth Sciences
University of Utah

Abstract

Applications of X-ray micro CT for the 3D quantitative characterization, analysis, and simulationof particle/particle bed features, porous structures, phase definition and composition, andmaterial damage will be discussed.  For example, fundamental properties of multiphaseparticles are described in 3D including size, shape, surface area, and spatial variation incomposition.  In addition, 3D pore network structures are identified and used to simulateconstrained fluid flow using the LB method for computational fluid dynamics.  Finally,mechanical properties of multiphase materials are described in 3D including crack size anddensity as well as micro FE analysis of porous structures.

Biography

J.D. Miller is the Department Chair and Ivor Thomas Distinguished Professor ofMetallurgical Engineering at the University of Utah.  He is the recipient of numerous awards andhas served on the faculty at the University of Utah for 41 years.  Professor Miller is a member ofthe National Academy of Engineering and a Distinguished Member of SME.  In 2007 hereceived an Honorary Ph.D. degree from the University of Pretoria in South Africa and anHonorary Professorial Appointment at Central South University, Changsha, PRC.  Morerecently, in 2008, Miller was recognized as a Distinguished Professor of MetallurgicalEngineering at the University of Utah.


Computational Exploration of Domain Self-Accommodation and Self-Assembly in Ferro-Systems

Tuesday, April 7, 2009 3:00 – 4:00 pm
Room G05, Rekhi Hall

Yu U. Wang
Department of Materials Science and Engineering
Virginia Tech

Abstract

In materials science and engineering, self-organized microstructure formation not only directlydetermines the properties and performance of materials, but also provides powerful routes tomaterials design and processing. This talk focuses on the formation and evolution of domains inferro-systems. Two particular examples are considered, namely, ferroic crystals and ferrocolloids. Computer modeling and simulation based on the Diffuse Interface Field Approach(DIFA) will be presented, and applied to the cases of self-accommodation of polar structuraldomains in ferroelectric materials and self-assembly of dipolar particles in ferro-colloids. It isshown that the engineering of self-accommodating domain microstructure and the control ofdomain evolution kinetic pathway during inter-ferroelectric phase transformation provideeffective means to achieve unique combinations of large, reversible and anhysteretic fieldinduced strain attributes. Computational analysis of nanodomain diffraction is also performed totake into account the coherent scattering and interference effects, and to establish links to insitu experiments. In the case of ferro-colloids, it is demonstrated that colloidal particles ofvarious dipole moments, charges, shapes, sizes, and capillary forces within two-phase liquidscan self-assemble into a variety of novel microstructures.

Biography

Dr. Wang joined the Department of Materials Science and Engineering at VirginiaTech in 2004 as an Assistant Professor. He received B.E. degree from University of Scienceand Technology of China in 1994 and Ph.D. degree from Rutgers University in 2001, both inMechanical Engineering. From 2001 to 2004, he worked as postdoctoral researcher in theDepartment of Materials Science and Engineering at Rutgers University. His research focuseson materials theory, modeling, and simulation. Currently, he is working on phase transformingmaterials for advanced properties, colloidal particle self-assembly for novel microstructures,nanodomain diffraction analysis, and development of the Diffuse Interface Field Approach tonew applications


Nanoparticle Materials for Printed Electronics Applications

Friday, April 3, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Professor Jon J. Kellar
Department of Materials and Metallurgical Engineering
South Dakota School of Mines and Technology
Rapid City, SD

Abstract

A variety of silver-based nanoparticles have been manufactured using several processingmethods.  The long-term goal of these nanoparticles is for their use in inks for printedelectronics applications.  Initial work has concentrated on control of particulate manufacturingtechniques, mainly with respect to size and shape.

Characterization of the nanoparticles has been performed using a suite of techniques scanningelectron microscopy, transmission electron microscopy, Raman spectroscopy and x-raydiffraction.

Traces of silver inks were made using the maskless, mesoscale material deposition (M3D).These lines were thermally cured after which the line conductivity was measured.  Atomic forcemicroscopy and differential scanning calorimetry were used to characterize the silver traces.


Science and Engineering of Materials for Electrochemical Energy Conversion and Storage Technologies

Monday, March 23, 2009 4:00 – 5:00 pm
Room 610, M&M Building

Dr. Wei Lai
Materials Science and Engineering
Massachusetts Institute of Technology
Cambridge, MA

Abstract

The supply of renewable energy is one of the greatest challenges facing humankind in the 21st century. The intermittent nature of most renewable energysources, require energy conversion and storage to link the energy supply withenergy demand. Electrochemical energy conversion and storage devices (fuelcells, batteries, etc) are clean and efficient technologies allowing direct exchangebetween electrical and chemical energy. However, fundamental research onmaterials properties and device architectures is needed to improve the energydensity and cost characteristics of current materials and exploration of futurecandidates.  In this talk, I will discuss (1) the mixed ionic and electronic conductionof ceria as an intermediate temperature solid oxide fuel cells material; (2) theelectrochemistry of a new high density porous electrode microstructure for lithiumbatteries and demonstration of a ultra-high density cubic millimeter scalemicrobattery using this porous electrode approach with a new packagingtechnology


High Resolution X-ray Metrology in Modern Semiconductor Manufacturing

Friday, March 20, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Professor Richard J. Matyi
College of Nanoscale Science and Engineering
SUNY – University at Albany
Albany, NY

Abstract

X-ray analytical and metrology methods are becoming increasingly important for advancedsilicon semiconductor fabrication. Vendors now market state-of-the-art X-ray tools for the routineanalysis of parameters such as layer thickness, chemical composition, strain relaxation, andinterfacial roughness. The recent integration of X-ray diffraction and reflectivity systems into fabcompatible process metrology tools suggests that the importance of these techniques will onlyincrease with time. Here we discuss some basic principles of X-ray methods and will describethe capabilities and limitations of these approaches for a variety of semiconductor processmetrology and characterization. Some specific examples of materials that have been studiedwith high resolution X-ray methods include (1) strained Si-Ge and Si-C heterostructures, (2)silicon-on-insulator and strained SOI material, (3) ultra-thin high-k dielectrics, (4) copper-basedmetallization systems, (5) low-k interlayer dielectrics, and (6) materials used in extremeultraviolet lithography.

Biography

Richard J. Matyi received his degrees in Materials Science and Engineering from NorthwesternUniversity (B.S., 1975; Ph.D., 1983) and the Massachusetts Institute of Technology (S.M., 1976). From 1982through 1988 he was a Member of the Technical Staff at Texas Instruments, where he worked in materials analysisby X-ray methods and molecular beam epitaxy growth of electronic device structures. In 1988 he joined the facultyof the Department of Materials Science and Engineering at the University of Wisconsin – Madison where hisresearch focused on the development of advanced X-ray methods as well as epitaxial growth processes and ionsolid interactions. Dr. Matyi left Wisconsin in 2000 to join the National Institute of Standards and Technology wherehis work included precision X-ray metrology and the application of X-ray methods to semiconductor manufacturingprocesses. In 2004 Dr. Matyi joined the State University of New York at Albany as a Professor and Senior Scientistin the College of Nanoscale Science and Engineering. His research at Albany centers on the fabrication ofnanostructures from various materials (primarily elemental and compound semiconductors) and theircharacterization with X-ray probes, particularly high resolution X-ray diffractometry and reflectometry.


Incipient Flocculation Molding – A Ceramic Forming Process

Monday, March 16, 2009 4:00 – 5:00 pm
Room 610, M&M Building

Steven Arrasmith
New York State Center for Advanced Ceramic Technology
Alfred University, Alfred, NY

Abstract

Incipient Flocculation Molding (IFM) was conceived as a new near-net-shape forming techniquefor ceramic components with the intent of avoiding the problems commonly associated withconventional ceramic powder injection molding (CPIM) systems.  The novel and advantageousaspects of IFM arise from its unique mechanism for controlling the states of flow and quiescenceof the ceramic particles during the forming process.  Conventional CPIM systems disperse theceramic particles in a matrix of high molecular weight wax or polymer that melts or solidifies tocontrol flow.  There is no wax/polymer matrix in the IFM technique.  The ceramic particles aredispersed in a liquid solvent and the interparticle forces are manipulated to control the fluidity ofthe system through the use of a temperature-dependent deflocculant.  An immediate advantageis that the system has the rheological characteristics of a pourable slurry rather than a viscous,plastic mass.  This assists in mixing, dispersion, mold filling, and permits the use of finer,submicron ceramic powders that possess superior sintering properties.The processing solvent can be quickly eliminated from the molded component by evaporation,avoiding a long debinding process.  Only the dispersant, amounting to 1-2 wt%, remains to bequickly burned-out in the early stages of sintering.  To test and demonstrate the IFM concepts, aceramic-dispersant-solvent system was developed to mold and sinter sample rods.  Theconcepts developed for IFM have potential applications in other ceramic forming processes,such as extrusion, slip casting, screen printing, and rapid prototyping.


Advances in Multiferroic Materials

Friday, March 6, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Dwight Viehland
Virginia Tech

Abstract

Multi-functional materials can respond to more than one external stimulus. Oneimportant family of such materials would be those with magnetization-polarizationinteractions: however, prior searches for such systems with strong exchange haveproven elusive. In this talk, we will discuss advances in magnetoelectric materials.Investigations of multi-ferroic behavior will be present in magnetoelectric (i) singlecrystals and epitaxial films; and (ii) laminate composites of piezoelectric andmagnetostrictive layers. We will demonstrate that strong interaction can beachieved between the spin and polarization subsystems. The results offer anapproach to a complete electromagnetic packaging material: which could haveimportant ramifications in sensors, voltage reading of spin states, powerelectronics, and antennas.