The aging behavior of thin piezoceramic plate

Compositions were based on the Pb[(Zr,Ti)_1-x(Mn,Sb,Nb) _x]O₃ system with x from 0.06 to 0.2. Pb-site vacancy is liable to occur on the surface of a sintered PZT plate. A surface layer composed of surface states is generated and plays an important role for a plate with a thickness smaller than 250 μm. Because the intrinsic property is nonpiezoelectric, the surface layer tends to decrease piezoelectric properties and aging rate. The influence of the surface state on aging is by way of the induced space charge, which gradually disappears and has no effect on aging rate after long time (>100-h) periods. Surface-polishing can degrade the PbO-deficient surface layer. A longer sintering duration enhances the surface effect through more Pb-site vacancy generation. The increase of the x value tends to shift phase toward the rhombohedral phase and reduces the aging rate