Domain patterns and super-elasticity of freestanding BiFeO3 membranes via phase-field simulations. (15th April 2021)

• Record Type: Journal Article
• Authors: Peng, Ren-Ci; Cheng, Xiaoxing; Peng, Bin; Zhou, Ziyao; Chen, Long-Qing; Liu, Ming
• Is Part Of: Acta materialia. Volume 208(2021)
• Publication Date: 2021-04-15
• Subjects: Ferroelectric -- Super-elasticity -- Phase transition -- Domain evolution -- Phase-field simulations; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2021.116689
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Super-elasticity of functional ferroelectric oxides offers promises for integrating ferroelectric films into flexible electronics. However, super-elastic deformation is a complex phenomenon related to possibly multiple concurrent mechanisms. Fundamentally understanding how multiple mechanisms contribute to the super-elasticity of ferroelectric oxides is crucial to realizing their potential flexible electronic applications. Here, we employ phase-field simulations to model the dynamics of ferroelectric domain patterns of freestanding BiFeO3 membranes to understand the origin of their super-elasticity under substantial bending deformation (5% strain). It is demonstrated that both a reversible Rhombohedral-Tetragonal (R-T) phase transition and a nearly reversible domain evolution of BiFeO3 membranes contribute to accommodating the large deformation and thus their super-elasticity. The dynamics of domain evolution also reveal the formation of an exotic ferroelectric vortex and polarization rotation before the phase transition. We constructed a diagram of phases and domain patterns as a function of the membrane thickness and bending angle, which allows one to readily predict the emergence of T phase and ferroelectric vortex in bent BFO membranes. These results not only provide fundamental understanding of mesoscale super-elastic mechanisms but also reveal exotic domain states of ferroelectric membranes. Graphical abstract: Image, graphical abstract