The effects of sieving method and poling approach on the internal bias field in donor doped pzt ceramics

In this investigation, the internal bias field in donor doped PZT ceramics was investigated through measuring both the electric hysteresis loops and the butterfly loops. The effects of both poling approaches and sieving methods on the internal bias field were examined. It was found that a sparse sieving technique, which leads to more defects and high porosity in PZT ceramics, may induce a larger internal bias field than a dense sieving one. Meanwhile, for the sparsely sieved PZT ceramics, a sample poled by an impact electric loading at room temperature has fairly good piezoelectricity and a negligible internal bias field, while a sample poled with field application above the Curie point or at 120oC has a considerably large internal bias field. Space charge concentration near the grain boundary defects and pores after poling is thought to be the cause of the distinct internal bias field.