Low dielectric constant of MeV ion-implanted poly(vinylidene fluoride)

Abstract

Poly (vinylidene fluoride)(PVDF) samples were implanted by using high energy (MeV)F2+ and Cl2+ ions. We observed that AC dielectric constant of the ion-implanted PVDF samples decreased from 10.5 to 2.5 at 1 kHz as the ion dosage increased from 1011 to 3 × 1014 ions/cm2. From differential scanning calorimetry experiments, we observed that PVDF samples become more disordered state through the ion implantation. The decrease of the number of bonding of C-H and C-F and the increase of unsaturated bonding were observed from X-ray photoelectron spectroscopy experiments. The emission of HF and H2 molecules during the ion implantation was detected by residual gas analyzer spectrum. Based upon the results, we analyzed that the low AC dielectric constant of the MeV ion-implanted PVDF samples originated from the reduction of polarization due to the structural change of the CF2 molecules in the MeV ion-implanted PVDF samples.