Poling rates for films of polyvinylidene fluoride

The growth of the pyroelectric coefficient p (T) of 6-μm films of polyvinylidene fluoride during poling with a field of 100 MV m−1 was measured for the poling temperatures Tp=100, 80, 60, 40, and 20 °C. Decreasing Tp greatly reduced the growth rate of p (T), but not the value of p (T) attainable by prolonged poling. For the best poled films p (T) increased with the film temperature T from 30 μC m−2 K−1 at 0 °C to 55 μC m−2 K−1 at 80 °C. The poling period required for p (20 °C), the room-temperature value of p (T), to reach 25 μC m−2 K−1 ranged from 0.5 min at Tp=100 °C to 8000 min at Tp=20 °C.