Piezoelectricity of Poly (vinylidene Fluoride) under High Pressure

Abstract

Pressure dependence of piezoelectric stress constant e 31 , dielectric constant ε 3 , electrostriction constant κ 31 , and Poisson's ratio m 31 of poly (vinylidene fluoride) film were measured. A new method for measurement of m 31 under high pressure was designed. The observed e 31 which decreased with increasing pressure was well explained by the composite model theory proposed by Wada and Hayakawa. Pressure dependences of the fractional contributions of κ 31 and m 31 to e 31 were clarified and the decrease of e 31 was revealed to come from the decrease of m 31 due to the increase in bulk modulus of amorphous phase.