Piezoelectric Properties of the 1-3 Type Porous Lead Zirconate Titanate Ceramics

Porous lead zirconate titanate (PZT) ceramics are of great interest for hydrophones and medical imaging applications. The 0–3 type and 3–3 type porous PZT ceramics have been extensively discussed these years but the 1–3 type PZT ceramics have seldom been reported. This paper describes the fabrication process to obtain such 1–3 type porous PZT ceramics with one-dimensional pore channels by using tert-butyl alcohol-based directional freeze-casting method, and presents analysis of both microstructure and functional properties. The 1–3 type porous PZT ceramics with porosity ranging from 28.1% to 68.7% were fabricated by adjusting initial solid loading. With the increase of porosity, relative permittivity (ɛr) decreased slightly and longitude piezoelectric coefficient (d33) exhibited only a small decline, which could be attributed to the special 1–3 type porous structure. The resultant samples with 61.3% porosity possessed a high value of hydrostatic figure of merit, >100 times higher than that of dense materials. The acoustic impedance (Z) showed a linear dependence on porosity with the lowest magnitude reaching 1.3 MRayls (106 kg·(m2·s)−1), matching very well with biological tissue or water.