Anisotropic mechanism on distinct transition modes of tip-activated multipolorizaion switching in epitaxial BiFeO3 films

Abstract

Based on the extended Kittel’s law, an anisotropic mechanism has been developed to investigate the complex multipolarization switching in (001) and (110) epitaxial BiFeO3 films, under a biased-tip field. Switching inhomogeneity and domain wall width evolution have been specifically accounted for. It has been found that distinct switching modes, i.e., the breakdown mode of 71°-switched domain and the activation mode of 180°/109° switching, exist and dominate the switching orders within switching process. Our predicted switching orders show excellent agreements with the existing experimental data and phase-field results. A two-step procedure is also proposed to fabricate single-phase 71° ferroelastic domain array of controllable density using (001) BiFeO3 films, which is favored in practice to significantly enhance the magnetoelectric coupling and photovoltage.

Effects of volume evolution of static and dynamic polar nanoregions on the dielectric behavior of relaxors

“…1(c) could also be stabilized to relax the stresses of PNRs, which may be used to explain the measured perpendicularity 13 of PNR polarization to that of the matrix. Besides, once the dimension of remaining medium is less than a critical size, 11,14 both high-aspect-ratio DWs and irregular stress field 7 will appear and persist at low Ts.…”