锆钛酸铅陶瓷电退化后的自我回复及再退化机理的研究

Lead Zirconate Titanate as one kind of piezo-ceramic, because of its good piezoelectrical properties and low material cost, is widely used in various electro-mechanical equipments. Piezo-ceramic will undergo an electrical degradation process after applying an electrical field, and the degradation process represents as the decrease of the resistance and the decay of the piezoelectrical properties. This electrical degradation phenomenon severely limits the lifetime and the performance of piezoelectrical products. After removing the applied electrical field, the resistance of the sample will increases as time goes and this phenomenon is so called self-recovery. If re-apply an electrical field across the sample, its resistance will rapidly decreases back to the value before the self-recovery process and this process is called re-degradation. The resistance decrease speed of the re-degradation process is approximitely 1/30 of the electrical degradation process. Many researchers have lots of achievements on the mechanisms of electrical degradation, but these theories cannot perfectly explain the mechanisms of the electrical degradation, self-recovery and re-degradation phenomena. Also, the current research works are only about the influence of the self-recovery and the re-gradation process on the change of sample's resistance. This project aims to investigate on the mechanisms of self-recovery and the re-degradation phenomena, and this work will be used for examing and improving the theories about electrical degradation. The works are significant for the applications and the developments of the piezoelectrical products.

锆钛酸铅作为压电陶瓷的一种，因其较好的压电性能，低廉的材料成本，被广泛应用于各种电子机械装置。压电陶瓷在电场的作用下会发生电退化现象，表现为电阻值逐渐减小，压电性能衰退。电退化现象严重地影响了压电产品的寿命与性能。当其所负载的电场被移除时，其电阻值会随着时间的推移而逐渐的自我回复，这个现象被称为自我回复现象。如果在压电陶瓷的电阻值自我回复一段时间后再施加电场的话，压电陶瓷电阻值会迅速降低至自我回复前的状态，这个现象被称为再退化现象，其电阻值下降的速度是电退化时的电阻值下降速度的约1/30。国内外学者对电退化现象的研究已取得了很多成果，但是这些理论并不能完整的解释电退化、自我回复和再退化现象，并且对自我回复和再退化的研究仅限于对所观察到的电阻值变化的描述。本项目旨在研究自我回复和再退化机理，并用于检验并完善电退化的理论。这对压电陶瓷产品的应用和推广有着重大的意义。

锆钛酸铅作为压电陶瓷的一种，因其较好的压电性能，低廉的材料成本，被广泛应用于各种电子机械装置。压电陶瓷在电场的作用下会发生电退化现象，表现为电阻值逐渐减小，压电性能衰退。电退化现象严重地影响了压电产品的寿命与性能。当其所负载的电场被移除时，其电阻值会随着时间的推移而逐渐的自我回复，这个现象被称为自我回复现象。如果在压电陶瓷的电阻值自我回复一段时间后再施加电场的话，压电陶瓷电阻值会迅速降低至自我回复前的状态，这个现象被称为再退化现象，其电阻值下降的速度是电退化时的电阻值下降速度的约3倍0。国内外学者对电退化现象的研究已取得了很多成果，但是这些理论并不能完整的解释电退化、自我回复和再退化现象，并且对自我回复和再退化的研究仅限于对所观察到的电阻值变化的描述。本项目通过对压电陶瓷电退化后的自我回复和再退化现象的研究，并对电退化过程中所生长的黑斑进行组织结构表征，提出了自我回复和再退化现象产生的机理，并进一步完善现有电退化理论，提出了多重电击穿理论。