Dielectric and ferroelectric properties of 1-3 composites containing thin PZT-fibers

PbZr_0.53Ti_0.47O₃ (PZT)-fibers were prepared by a sol-gel route and appropriate thermal treatment. The sintered fibers show negligible porosity of about 100 nm in diameter and a narrow grain size distribution, the grain sizes ranging from 1 to 5 μm depending on the sintering conditions. PZT-fiber/epoxy composites with 1-3 connectivity were prepared. Fiber volume fractions were adjusted from 20 to 70 vol.-%. Ferroelectric properties of composites with thicknesses between 0.05 and 0.5 mm are about 10 μC/cm² for the remanent polarization and about 15 kV/mm for the coercive field. During longtime cycling of up to 10⁶ cycles P_r nearly remains constant, E_c increases by 50%. A coupling coefficient k_t of up to 55% was measured. Perpendicular to the fiber direction a P_r of 0.8 μC/cm² and an E_c of 2 kV/mm were measured