Event
MSE Seminar - Dr. David Miltin, University of Alberta
Thursday, February 7, 2008
1:00 p.m.-2:00 p.m.
Rm. 2110, Chemical and Nuclear Engineering Bldg.
Annette Mateus
(301) 405-5207
amateus@umd.edu
Metastable Metallic Alloys for NEMS/MEMS, Nitride Growth Substrates and Hydrogen Storage
Presented by David Mitlin
Assistant Professor, Chemical and Materials Engineering, University of Alberta
Principal Investigator, NRC National Institute for Nanotechnology
Our group develops metallic nanocomposites in thin-film form for a variety of applications. These materials possess favorable properties such as near atomic-scale surface roughness; nanoindentation hardnesses that are an order of magnitude higher than of their crystalline counterparts; negligible internal and surface/differential stresses; enhanced catalytic activity; or the capacity to sorb significant amounts of hydrogen at low temperatures. In this presentation I will focus on the general alloy design methodology for creating amorphous-nanocrystalline thin film composites from binary systems of Al-Mo and Ni-Mo. I will discuss some of the fundamental aspects of the crystalline-nanocrystalline-amorphous transitions in these alloys from a standpoint of both bulk and surface structure evolution. I will also discuss the application of Al-Mo and Ni-Mo alloys as ultra-compliant electrically conductive NEMS and MEMS cantilevers, and as substrates for room temperature growth of highly oriented aluminum nitride. Finally, I will cover the hydrogen storage potential of destabilized Mg-Al alloys, processing and testing of MgH2 - carbon nanotube (CNT) powder mixtures, and the issues associated with directly imaging hydrides using TEM. These studies were performed with the aid of a variety of synthesis and analytical techniques including an array of nanofabrication and microfabrication routes, high-energy mechanical milling, TEM, AFM and XRD analysis, as well as thermodynamic modeling.
