Lead zirconate titanate

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Crystal structure
Perovskite structure of PZT
General
Surname Lead zirconate titanate
other names

Lead titanium zirconia

Ratio formula Pb [Zr x Ti 1− x ] O 3 (0≤ x ≤1)
Brief description

silvery-white odorless solid

External identifiers / databases
CAS number 12626-81-2
EC number 235-727-4
ECHA InfoCard 100.032.467
PubChem 159452
Wikidata Q883484
properties
Molar mass 303.06-346.42 g mol −1
Physical state

firmly

density

7.5-8.0 g cm -3

safety instructions
GHS labeling of hazardous substances
07 - Warning 08 - Dangerous to health 09 - Dangerous for the environment

danger

H and P phrases H: 360-373-410-302-332
P: 260-261-281-304 + 340-405-501
Authorization procedure under REACH

of particular concern : toxic for reproduction ( CMR )

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Phase diagram of PZT as a function of temperature and mixing ratio. P is the dielectric polarization vector ( spontaneous polarization ).

Lead zirconate titanate (PZT) is a ceramic with the empirical formula Pb [Zr x Ti 1− x ] O 3 (0 ≤ x ≤ 1) and belongs to the ferroelectrics family . The x means that due to their similar chemical properties , titanium and zirconium can be exchanged for one another in order to influence the ferroelectric properties of the compound.

The lead atoms are arranged in a cubic spatial structure . Lead-zirconate-titanate, like barium titanate , which is very similar to it , is usually perovskite . Several oxygen atoms face-centered cubic and one titanium or zirconium atom arranged “pseudo-body-centered cubic”, ie that the titanium atom actually adopts the body-centered cubic position above the Curie temperature . At temperatures below the Curie temperature (depending on the titanium content between 230 and 500 K), the titanium atom moves slightly out of its central position and the previously electrically neutral lattice becomes a dipole . This dipole lattice now has piezoelectric properties and is currently considered to be one of the most cost-effective materials for manufacturing high-performance piezo actuators. PZT is also preferably used as a storage element of a ferroelectric RAM .

PZT as piezoceramic

Hysteresis curve of doped PZT ceramics. The polarization P is plotted against the applied electric field strength E.

The properties of a PZT material can also be modified by incorporating foreign atoms ( doping ). The polarizability at different electric field strengths is of particular importance for piezoceramics . The doping creates so-called hard and soft ceramics, which differ in their hysteresis curve . Soft PZT materials are characterized by high remanence , but they show a change in the direction of polarization even at a lower field strength, the so-called coercive field strength . With hard PZT materials, the opposite is the case: the Weiss areas , also called domains, are more difficult to change using electrical fields. The material is therefore more difficult to shape ( harder ).

Web links

Individual evidence

  1. ↑ a b c data sheet Lead zirconium titanium oxide sputtering target, 50.8mm (2.0in) dia x 3.18mm (0.125in) thick, 99.9% (metals basis) from AlfaAesar, accessed on June 24, 2013 ( PDF )(JavaScript required) .
  2. ↑ Reade: Lead Zirconate Titanate (PZT) ( Memento of the original from June 23, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.reade.com
  3. ↑ Entry in the SVHC list of the European Chemicals Agency , accessed on July 17, 2014.