Effect of domain structure on dielectric nonlinearity in epitaxial BiFeO3 films

Abstract

Rayleigh analysis has been used to investigate dielectric nonlinearity in epitaxial (001)-oriented BiFeO3 films with engineered domain structures from single- to four-variant and stripe domain samples with 71° and 109° domain walls. Single-domain variant films display minimal irreversible contributions, whereas the ratio of irreversible to reversible contributions increases by approximately one order of magnitude as the number of variants increases to two- and four-variants, respectively. These measurements indicate that the density of domain walls and degree of domain wall complexity influence the number and strength of domain wall pinning sites.