Showing papers on "Lead zirconate titanate published in 1982"

Piezoelectricity of a high‐content lead zirconate titanate/polymer composite

Abstract: A binary system consisting of polyvinylidene fluoride (PVDF) and lead zirconate titanate (PZT) powder was investigated to determine its dielectric constant, piezoelectric constant, and Young’s modulus. An expression was obtained for the piezoelectric constant, and expressions for the dielectric constant and Young’s modulus were also mentioned. The calculated values had good agreement with the observed values for the composite with a large PZT volume fraction. The dielectric constant and the piezoelectric constant were 152 and 48.3×10−12 C/N, respectively, for the composite with the PZT volume fraction of 0.67. Changing the mixing ratio of PVDF and the fluorine elastomer, Young’s modulus was varied without changing the piezoelectric constant.

Composition-structure-properties dependences in solid solutions on the basis of lead-zirconate-titanate and sodium niobate

Abstract: The regularities relating electrophysical and structural parameters of solid solutions on the basis of lead-zirconatetitanate and sodium niobate are considered. An important structural peculiarity of these systems is a morphotropic region (MR)-region of morphotropic phase transition between tetragonal and rhombohedral (rhombic) phases. Understanding of the considered regularities makes easier the prediction of piezoceramic composition with the given properties for different applications.

Perforated PZT polymer composites

Abstract: Composites of lead zirconate titanate (PZT) and inactive polymers with 3-1 and 3-2 patterns and a method of fabrication thereof are described. Fabrication is accomplished by drilling holes in sintered PZT blocks and filling the holes with epoxy or some other inactive polymer. The influence of hole size and volume fraction PZT on the hydrostatic properties of the composite is evaluated. By decoupling the piezoelectric coefficients d33 and d31 in the composite, the hydrostatic coefficients are greatly enhanced.

Piezoelectric devices in Japan

Abstract: Quartz is still one of the most important piezoelectric materials, but the field of piezoelectric devices has seen great progress due to discovery and development of new excellent materials, especially piezoelectric ceramics consisting of ferroelectric compounds.The first practical devices made of barium titanate ceramics in Japan were ultrasonic transducers for fish-finders. At the beginning of the piezoelectric-ceramics-age, many other devices such as tuning forks, vibration reeds, and mechanical filters driven by piezoelectric ceramics were studied, but all of these devices were brought into production only after the more stable and efficient ceramic material, lead zirconate titanate ceramics, had been established. At present, the ceramic filters are mass-produced and enjoy a larger market than any other piezoelectric devices.In this paper, a brief history and the present status of research and development of piezoelectric materials and devices in Japan are described with some considerations of various...

Automatic performance testing of piezoelectric ceramics for power transducers

Abstract: The suitability of piezoceramics for transducers of high ultrasonic power is limited by dielectric and mechanical losses, which are intensified in the case of high electric field strengths and large mechanical stresses within the ceramics. A fully automatic system for measuring the mechanical losses and elastic coefficients of piezoceramics as a function of the elastic stresses is described.Measurements on lead zirconate titanate ceramics modified with Mn and Nb show the mechanical losses in the ceramic as well as its elastic coefficient to increase sharply as of a certain amplitude of mechanical stress. This mechanical threshold stress depends on the Mn mole fraction and degree of domain-wall stabilization in the ceramic.

Electrochemical Investigations of Lead Zirconate-Titanate Perovskites with Small and High Deviations from Stoichiometry

Abstract: Samples containing either nearly stoichiometric PbTi03, PbZr03, their pure or La-doped solid solutions, or highly PbO-deficient lead titanate and zirconate, were investigated by conductance and transference measurements. A totally ionic conductance was found in Ladoped samples; in all other cases the conductance was non-ionic, and of the p-type. A defect model, valid for nearly stoichiometric materials, which operates with ionized Pband Ovacancies in addition to electronic defects, yields a good description of the pressure dependence of the conductivity. Since the conductance of highly non-stoichiometric samples is independent of the PbO-deficiency, a chemical model is proposed, in which O-vacancies are structurally immobilized. This model is in agreement with Holmann's PbO-activity curves.

Piezoelectric properties of polycrystalline ferroelectrics in the low temperature region

Abstract: In this paper regularities in the change of piezoelectric properties in polycrystalline ferroelectrics of the lead zirconate titanate system (PZT) when they are cooled down to the temperature of 4.2 K are considered. Exposure to weak and strong electric fields and to mechanical stresses has been studied. A system of solid solutions Pb(Zr x Ti1-x )O3 + yMnO2 where 0.3 ≤ x ≤ 0.7, 0 ≤ y ≤ 3% has been our object of investigation, however, the revealed relationships have a more general character and apparently exist in other solid solution systems on the PZT basis as well as, to a large extent, in polycrystalline ferroelectrics in general.

Low frequency dielectric properties of pzt-8 ferroelectric piezoelectric ceramics

Abstract: This article presents results of our studies on PZT-8 polycrystalline ferroelectric ceramics of lead zirconate titanate. We have measured the dielectric constant and dielectric loss over a low frequency range (from . 100kHz-20MHz) and temperature range from room temperature to 500℃. The mechanism of dielectric loss, the relaxation process and the impurity effects are discussed. The main loss above Tc is attributed to conducting loss.We also propose some suggestions for improving electrical properties of PZT-8 ferroelectric ceramics.