Microwave sintering of fine grained PLZT 8/60/40 ceramics prepared via high energy mechanical milling

Fine powders of lanthanum modified (Pb0.92La0.08)(Zr0.60Ti0.40)O3 (PLZT 8/60/40) were processed by high energy mechanical ball milling. The ceramic pellets from these powders were sintered by using microwave sintering. Microwave processed ceramics were further investigated for their sintering behaviour, microstructure, dielectric and piezoelectric properties. The XRD pattern of PLZT shows a single phase formation except for the ceramics sintered at 1200 °C. Higher density and more uniform grain distribution were found for PLZT ceramics, microwave sintered at 1150 °C, in spite of having much shorter sintering time. As a result, comparable dielectric and piezoelectric properties were obtained for microwave sinterd PLZT ceramics. These show the grain size ∼1.2 μm, and the highest relative density ∼99.46%. The dielectric constant for the unpoled PLZT ceramics was found to be ∼2100. The piezoelectric charge (d33) and electromechanical coupling coefficient (kp) value for the PLZT ceramics were found to be, ∼574 pC/N and ∼67% respectively.