PB(ZR,TI)O-3 [PZT] FIBERS - FABRICATION AND MEASUREMENT METHODS

Fine scale lead zirconate titanate (PZT) and niobium substituted PZT ( Nb-PZT) piezoelectric fibers were fabricated from sol-gel processed vi scous ''sol'' using the ''spinning'' methodology developed for the con tinuous production of glass fibers. Subsequent drying and firing at ab ove 750 degrees C gave pure perovskite PZT and Nb-PZT fibers of 30 mu m in average diameter. Further densification and grain growth were evi dent for fibers fired at 1250 degrees C. Experimental methods for the determination of dielectric and polarization properties were developed to overcome inherent electric field difficulty relevant to fine scale fibers. The method to polarize fibers in a continuous manner was also demonstrated using 120 mu m diameter extruded PZT fiber. The dielectr ic constant and polarization hysteresis values of the sol-gel derived fine fibers were comparable with that of bulk ceramics. Preliminary si ngle fiber mechanical pull tests indicated that the tensile strength o f 30 mu m diameter PZT fibers were similar to that of bulk ceramics, b eing in the range of 35-55 MPa.