Lead zirconate titanate
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Lead zirconate titanate (
The material features an extremely large dielectric constant at the morphotropic phase boundary (MPB) near x = 0.52. These properties make PZT-based compounds one of the most prominent and useful electroceramics. Commercially, it is usually not used in its pure form, rather it is doped with either acceptor dopants, which create oxygen (anion) vacancies, or donor dopants, which create metal (cation) vacancies and facilitate domain wall motion in the material. In general, acceptor doping creates hard PZT while donor doping creates soft PZT. In general, soft PZT has a higher piezoelectric constant, but larger losses in the material due to internal friction. In hard PZT, domain wall motion is pinned by the impurities thereby lowering the losses in the material, but at the expense of a reduced piezoelectric constant.
PZT is used to make ultrasound transducers and other sensors and actuators, as well as high-value ceramic capacitors and FRAM chips.
Its chemical composition is . The increased piezoelectric response and poling efficiency near to x = 0.52 is due to the increased number of allowable domain states at the MPB. At this boundary, the 6 possible domain states from the tetragonal phase <100> and the 8 possible domain states from the rhombohedral phase <111> are equally favorable energetically, thereby allowing a maximum 14 possible domain states.
See also
External links
- For a full list of external links to MSDSs, spectroscopic data, commercial chemicals suppliers etc. for this compound, see [Chemical sources].
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