So let's start it
Lead-based piezoelectric ceramics that is a one type of materials.
It's has a lot of properties is
when It's is powders it's will pressed uniaxially and sintered at 1150 °C in oxygen atmosphere.
The dielectric constant and all piezoelectric properties increased with the addition of up to 1 mol.% of Ba2+ and then decreased notably when the higher concentration of the Ba2+ was used.
The Curie temperature shifted to lower temperatures by incorporation of Ba+2. Room temperature permittivity is showing the increment by substitution of Ba2+ up to one mol.% while the maximum permittivity at Tc is shifted toward the lower temperatures.
In the mean time, the shape of the permittivity-temperature peak is widening upon more Ba2+ substitution.
Fabrication of a single air-backed probe transducer with KNN-LT-LS base composition realized a measured -6 dB fractional bandwidth of 36.8% and an insertion loss of –8.36 dB, at a center frequency of 3.56 MHz. Permittivity and piezoelectric properties along polarization and coercive results indicate the soft piezoelectric behavior when Ba2+ is substituted in the KNN-LT-LS system.
In conclusion of finally , the importance of this system relative to other known lead-free piezoelectric ceramics are that (1) the piezoelectric and electromechanical properties are higher, (2) the biocompatibility is higher, thereby facilitating invasive/embedded medical ultrasound applications, and (3) the lower density results in a corresponding lower acoustic impedance, providing a more efficient match of acoustic energy into human tissue.