Effect of porosity on dielectric properties and microstructure of porous PZT ceramics

Porous piezoelectric materials are of great interest because of their high hydrostatic figure of merit and low sound velocity, which results in to low acoustic impedance and efficient coupling with medium. Porous lead zirconate titanate (PZT) ceramics with varying porosity was developed using polymethyl methacrylate by burnable plastic spheres (BURPS) process. The porous PZT ceramics were characterized for dielectric constant (ɛ), dielectric loss factor (tan δ), hydrostatic charge (dh) and voltage (gh) coefficients and microstructure. The effect of the porous microstructure on the dielectric constant and loss factor at frequencies of 10–105 Hz are discussed in this paper.