|Copyright:||AXTAL GmbH & Co. KG|
PMN-PT (Blei-Magnesium-Niobat/Blei-Titanat) und PIN-PMN-PT (Blei-Indium-Niobate/Blei-Magnesium-Niobate/Blei Titanat)
The PMN-PT (lead magnesium niobate-lead titanate) crystal family is known for its extremely high electromechanical coupling coefficient, high piezoelectric coefficient, high strain and low dielectric loss. As a result, ultrasonic probes and sensors of ferroelectric applications made from PMN-PT crystals are more sensitive and have broader bandwidth, and micro-actuators gain more strain.
PMN-PT crystal products are available in different shapes (plates, rings, wedges or boules), which can be provided as-sliced, as tested or electroded.
The second generation of this crystal family is PIN-PMN-PT (lead indium niobate-lead magnesium niobate-lead titanate). Such crystals are particularly attractive to applications where higher ambient temperature and higher power are required. Doped with indium (In) and sometimes with traces of manganese (Mn), PIN-PMN-PT has a higher transition temperature and higher coercive field (Ec) than PMN-PT, which makes it an ideal candidate for SONAR, infrared and pyroelectric applications.
Two typical applications of PMN-PT crystals are medical ultrasound, non-destructive testing (NDT) and energy harvesting. The superior coupling coefficient and electro-mechanical properties give PMN-PT crystal several advantages:
1) Very high sensitivity
2) Very broad bandwidth
These advantages translate into high imaging quality and high efficiency.
When high d33 and high k33 are desired, the crystal boules grown along  are used. The (001) plates are cut out of the boule and poled along , so the product performance is maximized and in-plate property variation is minimized. Below is a set of recommended domain engineering factors for each applications.
The following table shows the typical values of the main properties of PMN.PT, with two different percentages of PT content (lower: about 28%, higher: about 32%) in comparison with PIN-PMN-PT