Fabrication of PZN-PZT piezoceramics and ceramic fibers

By using lead acetate, zinc propionate, niobium ethoxide, zirconium propoxide and titanium butoxide as precursors, zinc and niobium modified lead zirconate titanate (PZN-PZT) gel fibers were fabricated by the sol-gel method. Prolyzed and sintered, The PZN-PZT ceramic fibers with a diameter of about 25 mu m were obtained. The SEM micrographs show that these ceramic fibers are dense and uniform. The X-ray diffraction patterns show that sintering temperatures will affect the crystal structure of PZN-PZT ceramics. When the sintering temperature higher than 1250 degrees C, the sintered ceramics and ceramic fibers have a pure perovskite structure. The densities of the bulk ceramic and ceramic fiber are 7.70 x 10(3)kg/m(3) and 7.80 x 10(3) kg/m(3) which were measured by Archimedes method. The electromechanical coupling coefficient k(t), piezoelectric coefficient d(33) and relative permittivity epsilon of the PZN-PZT fiber/epoxy 1-3 composite disk with 63% fibers loaded are 0.65, 403 pC/N and 1300, respectively. The k(t), d(33) and epsilon of the PZN-PZT ceramics made from the sol-gel powder are 0.48, 600 pC/N and 2627, respectively.