Brown University School of Engineering

Multiscale Atomistics for Defects in Electronic Materials

Add event to my Google calendar Add event to my Google calendar Share this event on facebook E-mail this event
Monday, February 06, 2012 4:00pm - 5:00pm

BROWN UNIVERSITY Joint Materials/Solid Mechanics Seminar Series “Multiscale Atomistics for Defects in Electronic Materials” Professor Kaushik S. Dayal Civil and Environmental Engineering Carnegie Mellon University Abstract: Ionic solids are important for electronic and energy storage/conversion devices. Examples include 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 fields that exist in vacuum 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." Monday, February 6, 2012 4:00-5:00 pm B&H Room 190