Enhancing piezoelectricity of PLZT ceramics by bismuth stearate coating via water-soluble defatted powder injection molding

Lead zirconate titanate-based piezoelectric ceramics (Pb 0·91 La 0·06 (Zr 0·58 Ti 0.42 ) 0.975 Nb 0·02 O 3 , PLZT) were prepared by water-soluble defatted powder injection molding using bismuth stearate as surfactant . The effects of bismuth stearate surfactant amount on the feed viscosity, water degreasing rate and electrical properties were studied. The results showed that the bismuth stearate coating reduces agglomeration between the PLZT powders and decreases the viscosity of the feed. During sintering, bismuth stearate is decomposed into bismuth oxide, which acts as sintering aid to increase the density of the sintered bismuth stearate-coated PLZT ceramics. Bi 3+ dissolves into the perovskite crystal lattice , which increases the tetragonality factor and the content of tetragonal phase, and improves the dielectric, ferroelectric and piezoelectric properties of the bismuth stearate-coated PLZT ceramics. This study provides a novel modification method for the production of injection molded ceramics using a water-soluble binder system.