A Study on the Preparation and Dielectric Characteristic of $\beta$-PVDF Vapor Deposited Thin Films by Applied Electric Field Method

전계인가법을 이용한 $\beta$-PVDF 증착 박막의 제조와 유전특성에 관한 연구

  • 박수홍 (인하대학교 전기공학과 기능성박막연구실) ;
  • 이덕출 (인하대학교 전기공학과 기능성박막연구실)
  • Published : 1998.03.01

Abstract

In this study, the $\beta$-Polyvinylidene fluoride(PVDF) thin films were fabricated by physical vapor deposition method. Also, the properties of dielectric relaxation were studied to understand carrier's behavior of PVDF thin films, to be regarded as the excellent piezo and pyroelectricity. In the process of vapor deposition, the $\beta$-PVDF thin films have been fabricated under the condition of the substrate temperature at 3$0^{\circ}C$, the applied electric field at 142.8kV/cm and the pressure at 2.0${\times}10^{-5}$torr. The dielectric properties of PVDF have been studied in the frequency range 10Hz to 1MHz at temperature from 30 to $100^{\circ}C$. The relative dielectric constant of $\alpha$ and $\beta$-PVDF were 6.8 and 9.8, respectively, under a frequency of 1kHz. Such a phenomenon was caused by the decrease in intermolecular forces originated by the phase-transition from the TGTG' molecular conformation to the TT planar zig-zag conformation. And the relative dielectric constant is increased as a measuring temperature increases, because of the reduction of relaxation time caused by the decrease of intermolecular force.

Keywords

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