First-Principles Investigation of Morphotropic Transitions and Phase-Change Functional Responses in ${\mathrm{BiFeO}}_{3}\mathrm{\text{\ensuremath{-}}}{\mathrm{BiCoO}}_{3}$ Multiferroic Solid Solutions

First-Principles Investigation of Morphotropic Transitions and Phase-Change Functional Responses in ${BiFeO}_{3} − {BiCoO}_{3}$ Multiferroic Solid Solutions

Oswaldo Diéguez and Jorge Íñiguez

Phys. Rev. Lett. 107, 057601 – Published 26 July 2011

Abstract

We present an ab initio study of the BFCO solid solution formed by multiferroics ${BiFeO}_{3}$ (BFO) and ${BiFeO}_{3}$ (BCO). We find that BFCO presents a strongly discontinuous morphotropic transition between BFO-like and BCO-like ferroelectric phases. Further, for all compositions such phases remain (meta)stable and retain well-differentiated properties. Our results thus suggest that an electric field can be used to switch between these structures and show that such a switching involves large phase-change effects of various types, including piezoelectric, electric, and magnetoelectric ones.