INFLUENCES OF THE CERAMIC MATRIX IN THE PROPERTIES OF FERROELECTRIC COMPOSITES BASED ON PVDF POLYMERS

摘要

Ferroelectric composites of Polyvynilidene Fluoride (PVDF) polymers and Lanthanum modified Lead Titanate Zirconte ceramics were synthesized based the solution method. The ratio of PVDF/PLZT was adopted as 25/75 of mass, with the ceramic powders having the concentration of lanthanum varying according the ratio La/Zr/Ti equal to 5/65/35, 9/65/35 and 11/65/35. The composites were characterized considering the structural and electrical factors. From the structural point of view it was found that me polymer composites have concentration of the polar phase (β phase) higher than 70%. It is also noted that synthesis route favors the formation of an amorphous phase, but it was not noticed a significant influence of the ceramics composition on the structural properties of composites. In the electrical point of view, it was clear that the variance of lanthanum concentration in the ceramics powders significantly modifies the values of dielectric constant and polarization of the composites.