Failure distribution and reliable analysis of ferroelectric ceramics under pulsed electric field

Abstract

Dielectric breakdown at high electric field plays an important role in the application of ferroelectric ceramics. In this paper, the failure probability versus electric shock time of ferroelectric ceramics under positive pulse electric field is analyzed statistically. The failure probability distribution of ceramics after 10 electric shocks is studied. Piezoelectric constant, <i>P-E</i> loop of ferroelectric ceramics after 10 thousand electric shocks are measured and the breakdown mechanism is discussed. The results indicate that the relation between failure probability and electric shock number of ferroelectric ceramics is shown by a bath-tube curve and the failure probability of samples after 10 electric shocks decreases by 4 orders of magnitudes compared with that of origin sample. According to the results of piezoelectric constant and <i>P-E</i> loop, the samples subjected to positive pulse electric field many times do not show obvious fatigue or aging effect. So pulse electric field loading at 4.5 kV/mm is close to non-destructive condition. Considering the spread speed of cracks, it can be found that the rupture of ferroelectric ceramics under pulsed electric field roots from extension and connection of multi-cracks from multi-defects.