Properties of VF2/VF3 ferroelectric copolymers: Electrical response under high pressure shock loading

The polarization of VF₂/VF₃ copolymers and their piezoelectric response under shock loading were studied with the objective of completing the understanding of the mechanical-electrical conversion process of piezoelectric polymers. The results achieved on a VF₂/VF₃ copolymer with 70 mol.% of VF₂ and 30 mol.% of VF₃ are given. The samples showed electromechanical coupling coefficients of 22.8% and dielectric loss of 0.094 at frequencies between 400 kHz and over 20 MHz. The materials were studied under quantitative, reproducible high-pressure shock loading in controlled impact loading experiments at peak shock pressures of from 0.4 to 30 GPa. To pressures of about 12 GPa the piezoelectric response was reproducible and appears to be modeled by a nonlinear dielectric, piezoelectric model. At higher pressures the responses are less reproducible but appear to be little affected by dielectric loss or electrical conduction