NanoScale Simulations of Materials Under Extreme Conditions
E.M. Bringa
CONICET & Instituto de Ciencias Básicas,
Universidad Nacional de Cuyo, Mendoza 5500, Argentina
Friday, February 25, 2011
2:30pm
Atkinson Hall – 4004
Abstract:
There is an increasing need for materials that need to perform under extreme conditions of pressure, temperature, and radiation exposure. Besides applications related to explosives, novel “extreme” materials are crucial in the new generation of fission and fusion reactors, which require significant technological and scientific leaps to be successful in increasingly contributing to the energy supply in the near future. In addition, given that the universe is not generally a gentle place, in order to understand its evolution it is necessary to understand what happens to materials under the extreme conditions provided by supernova explosions, severe meteor bombardment, etc.
Extreme pressure conditions often involve large deformation rates, greater than 106/s, leading to dramatic changes in the structure and mechanical properties of a material: transition from one crystalline phase to another crystal or amorphous phase, massive plastic activity leading to dislocations, twins, shear bands, etc. The characteristic lengths and times associated with these changes are nm and ns, and experimental tools able to deal with such spatial and time resolutions simultaneously are not currently available. Atomic scale computer simulations can, therefore, provide new insight and guide experiments, which mimic extreme conditions but can only offer in-situ analysis at a much lower resolution or ex-situ analysis.
I will discuss a few examples where molecular dynamics (MD) simulations at the nano-scale play a crucial role to understand complex experimental results for both nanocrystals and porous materials, including high porosity foams. I will also discuss links to other techniques, leading to multi-scale modeling approaches that are needed for technological applications.
Bio:
Dr. Bringa obtained his Ms.Sci. in Physics at Balseiro Institute (Bariloche, Argentina) in 1995, and his Ph.D. in Physics at the University of Virginia in 2000. He joined Lawrence Livermore National Laboratory in 2001 as a postdoctoral researcher, becoming a permanent staff member in 2006. During 2008 he returned to Argentina as an Independent Researcher for CONICET (the Argentinean Research Agency), and an Associate Professor at the Basic Science Institute of the University of Cuyo. His current research centers on computational materials science applied to problems in astrophysics, nanoscience and high-pressure physics, in collaboration with simulation and experimental groups in the U.S.A., Japan, Europe and South America.