Finite-temperature properties of Ba(Zr,Ti)O 3 relaxors from first principles

Abstract

A first-principles-based technique is developed to investigate the properties of Ba(Zr,Ti)O 3 relaxor ferroelectrics as a function of temperature. The use of this scheme provides answers to important, unresolved and/or controversial questions such as the following. What do the different critical temperatures usually found in relaxors correspond to? Do polar nanoregions really exist in relaxors? If yes, do they only form inside chemically ordered regions? Is it necessary that antiferroelectricity develop in order for the relaxor behavior to occur? Are random fields and random strains really the mechanisms responsible for relaxor behavior? If not, what are these mechanisms? These abinitio based calculations also lead to deep microscopic insight into relaxors. © 2012 American Physical Society.