FABRICATION OF TRANSPARENT LEAD LANTHANUM ZIRCONATE TITANATE CERAMICS FROM FINE POWDERS BY 2-STAGE SINTERING

Transparent lead lanthanum zirconate titanate (PLZT) ceramics were fabricated from fine powders using an inexpensive two-stage sintering technique. The powders were prepared by hydrolysis from low-cost inorganic precursors. In the two-stage sintering method, uniaxially pressed green pellets were densified to nearly theoretical values in an oxygen gas atmosphere during the first-stage sintering, at 1000-degrees-C for 1 h, and then residual, free lead oxide in the pellets was removed by second-stage sintering at 1100-degrees-C for 12 h. Transparent ceramic with an average grain size of 1.6-mu-m and a porosity of 1.3% was obtained. The transparency and dielectric characteristics of the present samples were compared with those of hot-pressed samples: The study of the polarization-field hysteresis loops of the present samples yielded a remanent polarization of 6.8-mu-C/m2 and a coercive field of 1.6 kV/cm. The low coercive field of PLZT ceramics could potentially reduce the driving voltage of electrooptic devices in many applications.