Effects of pore size and orientation on dielectric and piezoelectric properties of 1-3 type porous PZT ceramics

Porous PZT ceramics have drawn an increasing amount of interest in recent years due to their superior properties compared with the dense material. However, researchers have usually dedicated effort to 0-3 and 3-3 type porous PZT ceramics and little attention has been focused on 1-3 type. The 1-3 type porous PZT ceramics with high porosity were fabricated in this study by freeze-casting process. All samples possessed high piezoelectric coefficient (d(33)) with high porosity owing to the special one-dimensional ordered porous structure along the poling direction. The d(33) values increased by either improving the pore channel orientation level or decreasing pore size. The relative permittivity improved only with the enhancement of pore channel orientation level. The acoustic impedances ranged from 1.45 to 1.35 MRayls which could match well with those of biological tissue or water; therefore, this material would be beneficial in hydrophone applications. (C) 2010 Elsevier Ltd. All rights reserved.