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

Abstract

PbZr/sub 0.53/Ti/sub 0.47/O/sub 3/ (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 /spl mu/m 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 /spl mu/C/cm/sup 2/ for the remanent polarization and about 15 kV/mm for the coercive field. During longtime cycling of up to 10/sup 6/ cycles P/sub r/ nearly remains constant, E/sub c/ increases by 50%. A coupling coefficient k/sub t/ of up to 55% was measured. Perpendicular to the fiber direction a P/sub r/ of 0.8 /spl mu/C/cm/sup 2/ and an E/sub c/ of 2 kV/mm were measured.