Dielectric properties of PVDF thin films doped with 3 wt.% of RCl3 ( R = Gd or Er)

The dielectric permittivity (epsilon '), electric modulus (M), and ac conductivity ( sigma (ac)) of pure polyvinylidene fluoride (PVDF) and PVDF containing 3 wt.% RCl3 ( R = Er or Gd) were measured. The incorporation of 3 wt.% of ErCl3 or GdCl3 within the PVDF matrix is found significantly to increase its epsilon ' and sigma (ac). All investigated samples show different relaxation processes within the studied temperature and frequency ranges. The first process is alpha(a)-relaxation, which occurs around the glass transition temperature, T-g. The second process is alpha(c)-relaxation, which is associated with the molecular motions in the crystalline region of the main polymer chain. Third is the rho-relaxation which observed for pure PVDF at low temperatures and high frequencies. The frequency dependence of sigma(ac) shows that the conduction mechanism for pure PVDF and PVDF containing 3 wt.% of RCl3 is correlated barrier hopping ( CBH). The binding energy of the carriers was calculated based on the CBH model. Finally, the results obtained in this work are discussed and compared with those for 3 wt.% LaCl3- doped PVDF and similar materials. (C) 2014 Author(s).