Showing papers on "Lead zirconate titanate published in 1978"

The piezoelectric bimorph: An experimental and theoretical study of its quasistatic response

Abstract: Plates of the piezoelectric ceramic lead zirconate titanate of thickness approximately 150 mu m adhesively bonded to beryllium copper plates of comparable thickness form so-called bimorph elements. The electromechanical behaviour of such elements is studied under quasistatic conditions. Features dealt with include electrical poling, hysteresis behaviour, transverse and longitudinal mechanical strain. A theoretical treatment is given and used to interpret the measurements.

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.

Uniaxial-stress effects in a 95/5 lead zirconate titanate ceramic

Abstract: The response of a lead zirconate titanate ceramic to statically applied uniaxial stresses in the range 0–0.4 GPa has been investigated. The material studied was a niobium‐doped composition with the chemical formula Pb0.99Nb0.02(Zr0.95Ti0.05)0.98O3. Properties measured as a function of stress include electrical charge release from poled specimens, ferroelectric hysteresis‐loop behavior, macroscopic strains, and ultrasonic velocities. Data from the experiments exhibit anomalous behavior at low‐stress levels (0.05–0.2 GPa). Comparison with similar data obtained under conditions of hydrostatic pressure indicate that the anomalies observed in the uniaxial‐stress experiments are caused by domain‐reorientation processes rather than by the ferroelectric to antiferroelectric phase transition. This transition occurs at 0.32 GPa under hydrostatic‐pressure conditions, but no evidence for it is seen in the uniaxial‐stress measurements to 0.4 GPa. The relationship of the present results to other uniaxial‐stress studies...

Molten salt synthesis of lead zirconate titanate solid solution powder

Abstract: Sodium chloride and/or potassium chloride is added to an aqueous suspension of the oxides of lead, titanium and zirconium and stirred until the suspension converts to a gel which is then heated evaporating the water and melting said chloride in which the oxides dissolve and react precipitating lead zirconate titanate.

Molten salt synthesis of modified lead zirconate titanate solid solution powder

Abstract: Sodium chloride and/or potassium chloride is added to an aqueous suspension of the oxides of lead, titanium, zirconium and cationic modifier and stirred until the suspension converts to a gel which is then heated, evaporating the water and melting said chloride in which the oxides dissolve and react precipitating modified lead zirconium titanate.

Optically induced birefringence change in la-doped lead zirconate-titanate ferroelectric ceramics

Abstract: Optically induced birefringence change (OIBC) in PLZT is considered in view of space charge formed by photoexcitation of carriers. On the basis of optical measurements it is shown that, in general, complete screening of the applied field by space-charge field does not occur. Experimental results confirm theoretical calculations of electric fields and currents related to OIBC on the basis of a one-dimensional model.

Theoretical Density and PbO Deficiency of Pore-Free Transparent PLZT Ceramics

Abstract: Lanthanum modified lead zirconate titanate (PLZT) ceramics are useful for electrooptic devices. However, as far as the defect structure of PLZT, there are still some arguments. In this study, the single phase widths of the completely pore-free transparent PLZT x/65/35 ceramics have been studied as a function of La concentration x. The PbO loss data corresponding to the upper and lower limits of the single phase from the starting composition were measured by the thermogravimetric method in controlling atmospheres. Also, the density approach corresponding to the single phase region has been tried for the almost completely porefree specimens prepared by Two-Stage Processing. The defect structures are discussed so as to fit in both the single phase regions. Some electrical properties are measured for specimens with various PbO deficiency within the single phase region.

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.

Dynamic piezoelectric modulus of TsTS-19 lead zirconate-titanate ceramic

Abstract: Varieties of lead zirconate-titanate (PZT) piezoceramics are widely used in shock-tube experiments as the sensing element of pressure transducers [1-4]. In these experiments pressures up to 10 MPa are realized with characteristic durations of up to 100 Msec. There is no unified method for the calibration of such pressure transducers. Static calibration is used in [2], and in [4] a piezoelectric transducer is calibrated according to the mean pressure level in the detonation products. In [i] the piezoelectric modulus ds, of a ceramic is determined by comparing the amplitude of the transducer electrical signal with the shock pressure calculated from the kinematic parameters of the shock wave. All this indicates the existing need for ascertaining the possible dependence of d33 on the rise time and amplitude of the acting pulse. Data on the dependence of dss on the rise time of a pressure pulse for the piezoceramic PZT 52/48 are given in [5].