The physical, optical and dielectric properties have been investigated in $Pb_{0.91}La_{0.09}(Zr_{0.65}Ti_{0.35})_{0.9775}O_3$ system. 9/65/35 PLZT powders were prepared by coprecipitation and conventional oxide mixing method.
The specimens were sintered in $O_2$ atmosphere at 1230℃ for 4 hours in the first stage of the process and subsequently heat-treated in atmosphere powders at 1250℃ for 15 to 60 hours in the second stage.
The coprecipitated-specimens sintered in the first stage showed higher density (99% of the theoretical density) and lower PbO loss than oxide-specimens.
It the second stage, the curie temperature, density and dielectric constant decreased with increasing sintering time due to the grain growth and PbO loss.
The oxide-specimens sintered at 1250℃ for 45 hours showed the highest transparency in $PbZrO_3$+10PbO atmosphere powder.
But in the case of the coprecipitated-specimens higher transparency was obtained in $PbZrO_3$ atmosphere powder.
