Article contents
Breakdown and Hysteresis in Thin Ferroelectric Polymer Films
Published online by Cambridge University Press: 25 February 2011
Abstract
Hysteresis loops obtained from sub-micron films of ferroelectric polymers show a maximum polarization which depends on the frequency of the driving field, the thickness of the film and the number of loops previously traversed (fatigue). We speculate that these effects result from changes in domain wall mobility. For films with thickness above 200nm, the hysteresis loops show no significant thickness dependence. This implies that the dimension of regions of field non-uniformity near the electrodes is less than 200 nm.
In ferroelectric polymers subject to a uniformly increasing field, the variation of breakdown strength with the field ramp-rate indicates that sample heating has a significant effect on the dielectric strength. At low ramp rates (below 100 MVm−1s−1) the heating in the sample is mainly due to Joule heating and the dielectric strength increases with increased ramp rate. At higher ramp rates the predominant heating mechanism is dipolar dielectric loss and the dielectric strength decreases with increased ramp rate. The two mechanisms combine to produce a maximum in the dielectric strength vs ramp-rate plot.
- Type
- Research Article
- Information
- Copyright
- Copyright © Materials Research Society 1992
References
- 3
- Cited by