Poling of hard ferroelectric PZT ceramics

Poling of hard ferroelectric ceramics is not an easy process. Pinning of domain walls due to defects prevents the material to be switched by moderate conditions of poling. In this paper, we try to explore a way to facilitate the poling process by defeating the counteracting defects in lead zirconate titanate (PZT). We focus on the structural and electrical effects that enhance the domain mobility, as reflected by hysteresis loops. Increased mobility leads to depinched hysteresis loops and consequently to easier poling and eventually to better piezoelectric properties. Different poling conditions were applied to ceramic samples sintered at different temperatures before and after hysteresis depinching. Dielectric parameters were measured after each poling state. The results showed that the hard ceramic can be efficiently polarized only after domain depinning, which can be done by various methods.