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The use of pulsed electric acoustic technique for measuring electric field profiles in ferroelectric ceramic
(Proceedings - International Symposium on Electrets, 2002-12-01) [Trabalho apresentado em evento]
The pulsed electric acoustic technique, PEA, have been usually applied to probe space charge profiles in polymers. In this work we show preliminary results obtained with lead zirconate-titanate and niobium, PZTN, ferroelectric ...
Stable and metastable ferroelectric polarization analyzed by the ramp voltage technique
(Proceedings - International Symposium on Electrets, 2002-12-01) [Trabalho apresentado em evento]
The study of the stable and the metastable ferroelectric polarization of poly(vinylidene fluoride), PVDF, was performed using two successive equal sign ramp voltages, mediated by a short-circuit period. Rates from 10 V/s ...
Electrode poling of cellular polypropylene films with short high-voltage pulses
(Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Annual Report, 2002-01-01) [Trabalho apresentado em evento]
Recently, piezoelectric cellular polypropylene (PP) was proposed as a new type of quasi-ferroelectric. The observed hysteresis of the charge density as a function of the electric field could be explained as field-dependent ...
Effects of thermal treatment on phase transitions and on the mechanical relaxation in poly(vinylidene fluoride)
(Proceedings - International Symposium on Electrets, 2002-12-01) [Trabalho apresentado em evento]
This work reports on the effects from thermal treatment in poly(vinylidene fluoride), PVDF, obtained with differential scanning calorimetry (DSC) and dynamic thermal analysis (DMA) measurements. It is shown that in successive ...