Piezoelectricity in uniaxially stretched poly(vinylidene fluoride)

Hysteresis characteristics, which are similar to those observed in ferroelectric crystals, are found in uniaxially stretched poly(vinylidene fluoride) under a high electric field above 300 kV/cm at room temperature. The electrostrictive constant q13 in poly(vinylidene fluoride) is determined for polarization below about 0.5 μC/cm2 at room temperature to be 0.9 cgs esu. The remanent polarization after the poling process can be easily eliminated with a sufficiently high sinusoidal electric field. This effect is confirmed by thermally stimulated currents before and after the depolarization process.