Preparation of Thin Film Polyvinylidene Fluoride Shock Wave Pressure Transducers

摘要

Thin film polyvinylidene fluoride transducers have been prepared by a poling procedure which involves the repeated cycling of the applied electric field over the ferroelectric hysteresis curve. Using the procedure, it is possible to prepare a uniformly poled transducer and to establish, with precision, the final remnant polarization. The remnant or permanent polarization is calculated by measuring the total poling charge and subtracting from it that which arises from the resistance and capacitance of the specimen. By this method the authors were able to prepare ten gages with the same remnant polarization with a precision of 0.5%. X-ray observations and measurements of density on an unpoled specimen show that the film is biaxially oriented, contains both alpha and beta phase crystals, and is 50% crystalline.