Discharge currents in dense and porous PZT films

Abstract

Discharge currents in short-circuit capacitors with dense and porous PZT films subjected by preliminary polarization are studied. It is shown that discharge currents can be characterized by the sum of exponential functions with the three characteristic relaxation times: 300–400 s, 50–80 s, and 10–20 s. On the assumption that discharge current is caused by relaxation of polarization charge (depolarization), it is established that the remanent polarization decreases after 20–30 min by 5–7% for the dense films and by 60–100% for the porous ones. Strong depolarization in the latter case is due to effect of a dead layer and defects.