Lab Home | Phone | Search
Center for Nonlinear Studies  Center for Nonlinear Studies
 Colloquia Archive 
 Postdoc Seminars Archive 
 Quantum Lunch 
 Quantum Lunch Archive 
 CMS Colloquia 
 Q-Mat Seminars 
 Q-Mat Seminars Archive 
 P/T Colloquia 
 Kac Lectures 
 Kac Fellows 
 Dist. Quant. Lecture 
 Ulam Scholar 
 CNLS Fellowship Application 
 Student Program 
 Past Visitors 
 History of CNLS 
 Maps, Directions 
 CNLS Office 
Thursday, March 08, 2012
10:00 AM - 11:30 AM
CNLS Conference Room (TA-3, Bldg 1690)


Multiscale Atomistics for Defects in Electronic MaterialsIonic

Kaushik Dayal
Carnegie Mellon University in the Mechanics, Materials, and Computing Group of the Department of Civil and Environmental Engineering.

ferroelectrics and solid oxides. Defects in these materials play a central role in enabling their properties: for example, the electromechanics of ferroelectrics occurs by the nucleation and growth of domain wall defects, and solid oxide ionic conduction is through the motion of point defects. I will talk about our efforts to develop multiscale atomistic methods to understand the structure of defects in these materials. These materials have long-range electrostatic interactions between charges, as well as electric fieldsthat exist over all space outside the specimen. I will describe a multiscale methodology aimed at accurately and efficiently modeling defects in such materials in complex geometries. Our approach is based on a combination of Dirichlet-to-Neumann maps to consistently transform the problem from all-space to a finite domain; the quasicontinuum method to deal with short-range atomic interactions, and rigorous thermodynamic limits of dipole lattices from the literature. We apply the method to understand the electromechanics of a ferroelectric under complex electrical loading. The research is joint work with PhD student Jason Marshall, whose work received the 2011 USNCCM Best Poster Award for "Multiscale Mechanics with Long-Range Electrostatic Interactions."

Host: Turab Lookman, T-4,, 665-0419