Showing papers on "Lead zirconate titanate published in 1983"

rf planar magnetron sputtering and characterization of ferroelectric Pb(Zr,Ti)O3 films

Abstract: Ferroelectric films of lead zirconate titanate (PZT) have been fabricated by rf planar magnetron sputtering. Films having a resistivity >106 Ω cm and a dielectric constant >800 at 300 K have been achieved using 100% oxygen as a sputtering medium, 10% excess PbO added to the target, and appropriate post‐deposition annealing. The sputtering rate is in the range 0.2–1.0 μm/h and varies with sputtering pressure and substrate temperature. Post‐deposition annealing affects both crystallinity and grain size, but incipient crystallization formed only in as‐grown films deposited at substrate temperatures >400 °C is essential for this process to be effective. A clear ferroelectric transition is observed at 350 °C, while the activation energy for dc conductivity of around 0.8 eV is consistent with bulk properties of PZT. The spontaneous polarization and coercive field measured from ferroelectric hysteresis loops is 20.75 μC/cm2 and 10 kV/cm, respectively. The optical transmittance of the films is determined by a Pb–Pb charge transfer band near 400 nm and this is a sensitive test of film stoichiometry.

Structural studies of manganese stabilised lead-zirconate-titanate

Abstract: Piezoelectric compositions Pb(MnuNbvNiwTixZry)O3 where u+v+w+x+y = 1.0 were studied by means of X-ray powder diffractometry, scanning electron microscopy and thermal analytical techniques. These studies showed that Mn is incorporated into the tetragonal lattice as trivalent ions at the Ti, Zr octahedral (B) sites.

Some aspects of the physics of piezoelectric ceramics

Abstract: This paper discusses some aspects of the physics of piezoelectric ceramics which depend considerably on the presence of mixed ferroelectric phases in these materials. The data which are available and problems which are yet to be studied may be divided into several categories. A more complete understanding of problems arising in some of these categories awaits growth of good quality single crystals of lead zirconate titanate (PZT).

Ultrasonic measurements in fine powders using a photoacoustic pulse-generation technique

Abstract: In this paper, we demonstrate the applicability of PA pulse generation for the monitoring of ultrasonic properties of powders, for example, uncured carbon-loaded epoxy resin powders, whose average particle diameter is ~15 μm. The acoustic pulse is generated by a short laser pulse (10-nsec or 1-μsec duration) of 1–10-mJ energy and is detected by a piezoelectric detector (polyvinylidene difluoride foil or commercial lead zirconate titanate transducer). This allows ultrasonic measurements over a broad range of porosity and pressure conditions, from loose unconsolidated powers to heat- and pressure-sintered pellets. For loose powders at atmospheric pressures (with a porosity of ~50%), the acoustic velocity is remarkably small (typically 3 × 103 cm/sec), and attenuation and dispersion are large. This appears to be the first demonstration of the use of a PA technique to measure ultrasonic properties in powders.

Device for varying phase and/or polarisation of the light wave running in an optical waveguide, and method for producing such a device

Abstract: The device consists of a body (2) made from ceramic, piezoelectric material, such as lead zirconate titanate, for example, which is polarised and carries electrodes (3, 4) on the outer surfaces. An optical waveguide (1) is fastened in a capillary duct of the body (2) by means of a rigid bonding agent (5). The direction of polarisation can extend parallel to the axis of the optical waveguide (1) or perpendicularly thereto. The capillary duct can be produced in a simple way by embedding a glass fibre in the starting oxide mixture for the body made from piezoelectric ceramic material. During firing of the body, the glass diffuses into the interior of the body, the capillaries being produced. The device according to the invention is applied, furthermore, in devices in which the phase and/or polarisation of a light wave running through an optical waveguide is to be influenced.

Lead zirconate-titanate piezoceramics prodn. - comprises calcining platelets sawn from larger sintered blocks before metallising and polarising

Abstract: In Pb zirconate-titanate piezo-ceramics prepn., the initial materials, e.g. PbO, TiO2 and ZrO2, are mixed, ground, reacted to Pb zirconate-titanate, ground, pressed to blocks, sintered at 1250-1300 deg.C. sawn to smaller ceramic platelets and lapped. Novelty consists in calcining the ceramic platelets at 1000-1100 (1055-1000) deg.C for 120-20 (40-20) min. before metallising and polarising. Platelet wt. loss by calcination is less than 1.5%. The piezo-ceramics can be used as electro-mechanical filters. The mechanical quality factor, Qm, is increased, e.g. to at least 1600 (at least 2000) without increasing the electro-mechanical coupling factor.

Phonon echoes in piezoceramic lead‐zirconate‐titanate

Abstract: Two‐pulse phonon echoes have been generated in piezoceramic lead‐zirconate‐titanate, using an electric field at twice the frequency of the ultrasonic waves. The echo properties with respect to pulse width, electric field, frequency, and temperature dependences have been studied. It is demonstrated how the phonon echo can be utilized in sorting the pure sound absorption from the grain scattering losses in a ceramic material.

Photomechanical effects in PZT

Abstract: A photomechanical effect has been observed in the piezoelectric sonar transducer ceramic, lead zirconate titanate (PZT) in which the material becomes measurably softer when illuminated with visible light. The phenomenon has been studied by stress relaxation techniques and attempts have been made to analyze the data in terms of a thermal activation analysis that had been successfully applied to PZT in the absence of illumination. The effect of light intensity on the stress relaxation was determined. The results are discussed in terms of the effect of illumination on the migration of non-180 degree domain boundaries.