Electrical boundary condition at the crack surface in ferroelectrics

Abstract Electrical boundary condition (EBC) at the crack surface has significant influence on the fracture behavior of ferroelectrics. Here, we characterized the electrical displacement (ED) response of ferroelectrics specimens with through cracks under cyclic electric field. The physical processes occurred between the crack surfaces are in situ observed. It is found that when the distance between the crack surfaces was smaller than a critical value, significant ED was measured, which cannot be rationalized by the previous EBCs. The appearance of bubbles and arcing between the crack surfaces demonstrates that dielectric breakdown occurs during electric field loading. These results imply that the EBC of the crack surface is permeable, and the dielectric breakdown process should be taken into consideration.