Abstract

Phase field model is employed to study some fundamental aspects of morphotropic phase boundary (MPB) ferroelectrics. MPB ferroelectrics offer the best electromechanical properties among all ferroelectric and piezoelectric materials. This talk will present some new insights gained into the underlying mechanisms responsible for the advanced piezoelectric behaviors around MPB. The new findings are composition-induced inter-ferroelectric phase transition, nanodomain microstructures of coherent ferroelectric phase decomposition, bridging domain mechanism for phase coexistence and the associated ferroelectric shape memory effect, grain size effects on the composition range of phase coexistence, and domain wall broadening mechanism for domain size effect of enhanced piezoelectricity.

 

Biography

Weifeng Rao received his B.S. degree in Engineering Mechanics and M.S. degree in Solid Mechanics, both from Tongji University (Shanghai, China) in 1999 and 2002, respectively. Before coming to Virginia Tech in 2005, he worked as a Lecturer at University of Science and Technology of China. He is currently pursuing his Ph.D. degree under the direction of Dr. Yu Wang. His work focuses on Materials Modeling and Computer Simulation of ferroelectric/piezoelectric materials.