A microstructural study of porous piezoelectric ceramics obtained by different methods

Effects of pre-polarization on the dielectric and piezoelectric properties of 0–3 type PIN–PMN–PT/PVDF composites

“…It is known that sound wave velocity in air is far lower than that in ceramic phase. Previous study showed that the acoustic impedance was sensitive to the porosity [30][31][32]. At relatively lower ceramic content (\80 vol%), the porosity is low and the monotonic increase of Z and C 33 of the 0-3 composites mainly originates from the introduction of more ceramic phase with higher acoustic impedance.…”

Modification of microstructure on PZT films for ultrahigh frequency transducer

“…Earlier studies have reported the dielectric and ferroelectric properties of porous PZT ceramics [8][9][10][11][12][13][14]. In comparison with the dense ceramics, the porous ones exhibit much lower dielectric constant and lower acoustic impedance, which makes them suitable for the fabrication of ultrahigh frequency transducers [15][16][17].…”

Influence of carbon black on slurry compositions for tape cast porous piezoelectric ceramics

“…As a consequence of a lower acoustic impedance (Z) [6,7], the transfer of acoustical energy to water [4] or biological tissues [5] is additionally improved when the material is porous. A low Z value, in fact, reduces the mismatch between the device and the media through which the signal is transmitted or received, leading to a more efficient acoustic wave transfer [8]. On the other hand introducing porosity reduces the electromechanical coupling (k) and piezoelectric charge (d) coefficients in the thickness mode and therefore lowers the piezoelectric response in respect to the dense material.…”