DEPARTMENT OF MATHEMATICAL SCIENCES

APPLIED AND COMPUTATIONAL MATHEMATICS SEMINAR

**Speaker:**Kaushik Dayal, Carnegie Mellon University

**Title: ***
Multiscale Atomistics for Defects in Electronic Materials
*

**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 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.

**Time:** Friday, March 11, 2016, 1:30-2:20 p.m.

**Place:** Exploratory Hall, Room 4106

Department of Mathematical Sciences

George Mason University

4400 University Drive, MS 3F2

Fairfax, VA 22030-4444

http://math.gmu.edu/

Tel. 703-993-1460, Fax. 703-993-1491