Inhomogeneous creep of polarization and strain around a circular hole in ferroelectrics under electric field: Experiments and modeling

The simulation of inhomogeneous creep around a circular hole in a solid of anisotropic ferroelectric is presented under various levels of constant electric potential condition from virgin state aiming for understanding the experimental situation by birefringence measurements. Due to the electric field concentration effect presented by the hole, the time dependent fields of stress, strain and polarization can be determined using the finite element method. It is found that the electric field concentration factor by a hole can achieve 6times of the applied loads and shows slightly time dependence; the creep of polarization and strains process is controlled by the local electric field magnitude, which governs the saturation of remnant polarization and strain. The result of principal strain difference around a hole agrees with the birefringence observation. This confirms the established birefringence-strain correlation by the previous experimental study.