Effect of poling conditions on the dielectric and piezoelectric characteristics of PZT ceramics

Two kinds of PZT ceramics: hard-type and soft-type, are studied in this paper. When the poling temperature is low (50°C), no matter how high is the poling field and how long is the poling time, the hard-type PZT ceramics cannot reach the optimum status. But when the poling temperature raises to 100°C or higher, the ceramics can reach the optimum status with lower poling field and shorted poling time, and the planar electromechanical coupling factor is higher than 0.60. For soft-type PZT, no matter how higher is the poling field and how long is the poling time, the ceramics can reach the optimum status, and the planar electromechanical coupling factor can reach higher than 0.60 for low temperature poling.