Dielectric property and ac conductivity of P(VDF-CTFE)-PLZST polymer-ceramic composite films

Abstract Free-standing and flexible polymer-ceramic composite films were fabricated using P(VDF-CTFE) 91/09 mol.% (VC 91 ) as polymer matrix and (Pb 0.94 La 0.04 )[(Zr 0.56 Sn 0.44 ) 0.84 Ti 0.16 ]O 3 (PLZST) nanoparticles as ceramic filler. All the VC 91 -PLZST composite films are dense and homogeneous in microstructure, and are flexible with a uniform thickness of about 5 μm. It is experimentally found that as the PLZST content increases, the dielectric constant of the composite films increases, while the dielectric loss decreases. Besides the glass-transition process, there is another relaxation process related to the motion of entire polymer chains of VC 91 . These two relaxation processes determine the frequency dependences and temperature dependences of the dielectric properties observed in the composite films. The ac conductivity of the VC 91 -PLZST composite films was investigated at different temperatures and the results indicate that the conductive mechanisms are related to the relaxation processes of the VC 91 matrix at different temperatures and all the VC 91 -PLZST composite films are good insulators.