The Role of Order in Pyroelectricity of Pvf₂

A series of studies of the pyroelectric effect in polyvinylidene fluoride indicates that reversible changes in the amount of order in the polymer films plays an important role in the pyroelectric effect. Experiments were conducted which showed that only one-half to two-thirds of the total pyroelectric effect can be accounted for on the basis of the usual primary and secondary effects. This observation led to the hypothesis that reversible changes with temperature of the crystallinity of the semicrystalline polymer might account for the rest. This hypothesis predicted that the crystallinity of the polymer should depend on the magnitude of an applied electric field. Experiments have been conducted in which this effect was observed.