Premium
Microstructural Evolution of Transparent PLZT Ceramics Sintered in Air and Oxygen Atmospheres
Author(s) -
Choi JongJin,
Ryu Jungho,
Kim HyounEe
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00861.x
Subject(s) - materials science , sintering , microstructure , ceramic , composite material , lead zirconate titanate , oxygen , porosity , layer (electronics) , partial pressure , mineralogy , ferroelectricity , optoelectronics , dielectric , chemistry , organic chemistry
Transparent lanthanum‐doped lead zirconate titanate (PLZT) ceramics were fabricated by air‐pressure sintering. When the PLZT (9/65/35) specimens were sintered in air, the microstructure was not uniform throughout the body; the outer region near the surface was completely dense, while the inner region of the body was porous. The thickness of the outer dense layer increased parabolically with sintering time. When the specimen was sintered in air at 1200°C for 8 h, the thickness of the dense layer was ∼0.25 mm. Therefore, when the specimen had a thickness of <0.5 mm, it was dense and transparent. This difference in microstructure was attributed to the formation of lattice vacancies as a result of PbO evaporation from the surface. The sintering atmosphere also was important in determining the thickness of the dense layer. The thickness was strongly dependent on the oxygen partial pressure of the atmosphere. The oxygen‐gas trapped in pores was deemed to migrate easily through the lattice vacancies. By sintering in an oxygen‐gas atmosphere at 1200°C for 8 h, a transparent PLZT with thickness up to 2 mm was fabricated.