Lead zirconate titanate

About: Lead zirconate titanate is a research topic. Over the lifetime, 7141 publications have been published within this topic receiving 150878 citations.

Electrical Conductivity in Lead Zirconate‐Titanate Ceramics

Abstract: Electrical conductivity was investigated in polycrystalline lead zirconate-titanate ceramics, with and without various dopants and stoichiometry, fabricated from chemical solutions and mixed-oxide powders. A multiphase packing-powder technique was used to control the stoichiometry of the system during sintering. The dc resistivity was measured by using a guard-ring method. Electrical conduction follows typical semiconductor behavior. Thermoelectric power measurements showed that hole conduction was dominant. Impurity ions which can serve as acceptors or donors significantly affect the conduction process. For undoped PZT the activation energy was 3.6 eV from 650° to 800°C and 1.4 eV at <650°C.

Single Element High Frequency (<50 MHz) PZT Sol Gel Composite Ultrasound

Abstract: A sol gel composite process has been used to produce lead zirconate titanate coatings in the thickness range of 3 to 100 pm on aluminum substrates. The complex permittivity (E&), elastic stiffness (cg), and the piezoelec- tric constant (h33) of the coating and the complex elastic stiffness (cz) of the substrate have been determined us- ing impedance measurements and a commercially available software program (Piezoelectric Resonance Analysis Pro- gram PRAP 2.0, TASI Technical Software, Kingston, On- tario, Canada). The complex components of the material parameters account for the losses within the film and the substrate. Sol gel composite films on aluminum have a di- electric constant of 220 with an imaginary component of 1% and an electromechanical coupling coefficient of up to 0.24 with an imaginary component of 3%. These films are applied to the fabrication of high frequency transducers suitable for ultrasound biomicroscopy (UBM). By combin- ing the sol gel composite material with existing transducer fabrication techniques, single-element focusing transducers have been produced that operate in the frequency range of 70 to 160 MHz. Devices have -6-dB bandwidths up to 52% and minimum insertion losses ranging from -47 to -58 dB. Real-time images of phantom materials and ex vivo biolog- ical samples are shown.

High-temperature electrical conductivity and point defects in lead zirconate-titanate

Abstract: The electrical conductivity and thermoelectric power of lead zitconate-titanate Pb(Ti0.47Zr0.53)O3 (PZT) have been studied at temperatures up to 1000°C in gaseous ambients with controlled partial pressures of both volatile components: lead oxide and oxygen. The experimental results show the small polaron conduction mechanism in PZT. The predominant point defects, as obtained from the oxygen pressure dependences of the conductivity and thermopower, are fully ionized vacancies of lead and oxygen with almost equal concentrations: [image omitted]

Ferroelectric properties of PZT thin films prepared by sputtering with stoichiometric single oxide target: Comparison between conventional and rapid thermal annealing

Abstract: The influence of growth conditions and post-annealing treatments on radio frequency (r.f.) magnetron sputtered lead zirconate titanate (PZT) thin films have been investigated. By adjusting the plasma discharge parameters, it is possible to control, with stoichiometric single oxide target, the film composition precisely. No excess lead was used either during sputtering (in the target) or during post-deposition annealing. The structural, microstructural and electrical properties have been systematically examined as a function of the annealing treatments. Perovskite structure was obtained by conventional annealing as well as by rapid thermal annealing. The films were dense and crack-free; the film orientation, the microstructure and the surface morphology are directly related to the thermal processes. The ferro-electric properties in terms of coercive field and remanent polarization are also very sensitive to the annealing treatments.

Evaluation of Imprint Properties in Sol-Gel Ferroelectric Pb(ZrTi)O3 Thin-Film Capacitors

Abstract: Studies of imprint properties have been carried out by electrical evaluation with pulse switching response and circuit modeling on sol-gel lead zirconate titanate (PZT) ferroelectric thin-film capacitors. The imprint properties were evaluated by measuring the switched and nonswitched charges after three different operations at high temperature, which consist of (1) fatigue by cumulative bipolar pulses, (2) exposure to a large number of positive unipolar pulses, and (3) exposure to a large number of negative unipolar pulses. The nonswitched charge without polarization reversal after being exposed to a large number of unipolar pulses was increased to be greater than switched charge with polarization reversal. This causes the decrease of a noise margin when the memory cell is read. This phenomenon is enhanced by the sample temperature above 75°C, the pulse height, and the amount of cumulative fatigue cycles before imprint. This phenomenon is also found in the Nb-doped PZT capacitor, which is a candidate for fatigue-free materials.