Improvements in Atmosphere Sintering of Transparent PLZT Ceramics

An improved atmosphere sintering process was developed for fabricating large transparent PLZT plates for electrooptic applications. Cold-pressed 9/85/35 PLZT slugs were sintered in O₂ in Pt crucibles for ∼45 min at 1180°C and were then heat-treated in air for 60 h at 1200°C in Al₂O₃ crucibles containing PbZrO₃ atmosphere powder. Transparent plates as large as 8.4 cm in diameter and I cm thick were thus fabricated. A mechanism is proposed which qualitatively accounts for the success of this process.