ELECTRICAL PROPERTIES AND MICROSTRUCTURES OF MICROWAVE SINTERED PZN-BASED CERAMICS

摘要

In this work, Pb(Zn_(1/3)Nb_(2/3))O_3 (PZN)-BaTiO_3 (BT)-Pb(Zr_(0.52)Ti_(0.48))TiO_3 (PZT) ceramics were prepared by solid phase reactions via Columbite method. Relevant oxide powders were mixed and processed using microwave sintering (MS) and conventional sintering (CS) techniques. PZN-PZT-BT ceramics using partially crystallized powders exhibited similar ferroelectric characteristics in polarization-electric field measurements regardless the sintering methods, but MS samples might show more dispersion in the dielectric constant curves as a function of frequency in the weak-field dielectric properties. However, MS specimens fabricated front fully crystallized powder exhibit much better electrical properties than the CS specimens. TEM investigations of PZN-PZT-BT ceramics reveal that the MS specimens often show smaller, less-uniform grains and more complicated domain arrangements may exist. Besides, the results imply that microstructures of the specimens can be improved using microwave sintering if well-crystallized powders were adopted, and therefore enhance the electrical properties.