Archive for March 2009

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

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.

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.

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.

Monday, March 2, 2009 4:00 – 5:00 pm
Room 610, M&M Building

Dr. Kathleen Sevener
Assistant Professor
Mechanical Engineering Department
Valparaiso University, Valparaiso, IN

Abstract

With the continuing interest in hypersonic flight, much work is focused on developing andcharacterizing ultra-high temperature ceramics (UHTCs) for leading edge applications andincorporating UHTCs into composites for hot structures. There is a lack of understanding of thetrue aerothermal effects on UHTC materials, which is required for optimization of UHTCcomposition.  While means to explore such effects are in progress within the aerospacecommunity, parallel efforts to develop UHTC compositions with improved properties areunderway.  This presentation will focus on work performed at AFRL to evaluate several HfB2-SiCUHTC compositions via isothermal anneals. Initial studies focused on the effect of compositionvariation. To establish a baseline on the materials, samples were subjected to furnace oxidationat 1500°C and 1600°C and the oxidation behavior was characterized via weight change,scanning electron microscopy, and energy dispersive spectroscopy. The baseline data werecompared to published data for similar compositions. Follow-on studies focused on the effect ofprocessing parameters for HfB2-20vol% SiC, the most promising candidate from the initialstudies. Milling time and consolidation method were varied to determine if the resultingmicrostructural changes would influence oxidation behavior. Results of these studies will bepresented and analyzed in the context of oxidation models under development at AFRL, andwith consideration to future applications of UHTCs on hypersonic vehicles.