Birefringence induced by antiferroelectric switching in transparent polycrystalline PbZr0.95Ti0.05O3 film

The most characteristic functional property of antiferroelectric materials is the possibility to induce a phase transition from a nonpolar to a polar phase by an electric field. Here, we investigate the effect of this field-induced phase transition on the birefringence change of PbZr0.95Ti0.05O3. We use a transparent polycrystalline PbZr0.95Ti0.05O3 film grown on PbTiO3/HfO2/SiO2 with interdigitated electrodes to directly investigate changes in birefringence in a simple transmission geometry. In spite of the polycrystalline nature of the film and its moderate thickness, the field-induced transition produces a sizable effect observable under a polarized microscope. The film in its polar phase is found to behave like a homogeneous birefringent medium. The time evolution of this field-induced birefringence provides information about irreversibilities in the antiferroelectric switching process and its slow dynamics. The change in birefringence has two main contributions: One that responds briskly and a slower one that rises and saturates over a period of as long as 30 min. Possible origins for this long saturation and relaxation times are discussed.