Andrew Rappe (University of Pennsylvania)

Date: Thu. October 27th, 2016, 4:00 pm-5:00 pm
Location: Rockefeller 301

Slush Structure and Dynamics in a Relaxor Ferroelectric

Ferroelectric materials undergo solid-solid structural phase transitions between phases with aligned dipoles and randomly oriented dipoles. Incorporating quenched Coulombic disorder by varying the charge of the ions on the lattice disrupts and changes the  of this transition; instead of a sharp transition in a small temperature range, these oxide alloys exhibit "relaxed" transition over 100-200 K and are called "relaxor ferroelectrics." In this talk I will describe how a first-principles based multi-scale model can reveal the dynamic and statically correlated motions of ions that lead to relaxor behavior, and I will discuss their promise for next-generation piezoelectric and dielectric material systems.