Lead Zirconate-Lead Titanate (PZT) Ceramics From Organic-Derived Precursors

1984 ◽  
Vol 32 ◽  
Author(s):  
R. G. Dosch
Keyword(s):  
Surface Chemistry ◽  
Lead Titanate ◽  
Lead Zirconate ◽  
Solution Chemistry ◽  
Reaction Products ◽  
Pzt Ceramics ◽  
Aqueous Surface ◽  
Hydrolysis Of ◽  
Direct Hydrolysis ◽  
Hydrated Zirconia

ABSTRACTOrganic-derived precursors can facilitate the preparation of PZT ceramics, particularly in the areas of processing and batch reproducibility. The use of partially alkoxide-derived precursors and completely organic-derived precursors has been studied. Two methods of alkoxide hydrolysis were evaluated for preparing zirconia which included direct hydrolysis in water and hydrolysis of alkoxide-base reaction products in acetone-H2O mixtures. The chemistry of these methods is discussed along with pertinent aqueous surface chemistry of the hydrated zirconia products. This work suggests that alkoxide-derived precursor properties are related to the solution chemistry used in their preparation.

Microwave Processing and Sintering of PZT and PLZT Ceramics

1988 ◽  
Vol 124 ◽  
Author(s):  
W. B. Harrison ◽  
M. R. B. Hanson ◽  
B. G. Koepke
Keyword(s):  
Lead Titanate ◽  
Microwave Sintering ◽  
Ferroelectric Properties ◽  
Lead Zirconate ◽  
Microwave Processing ◽  
High Density ◽  
Pzt Ceramics ◽  
Conventional Sintering ◽  
Processing Techniques ◽  
Fast Firing

ABSTRACTMicrowave processing techniques were established for all of the thermal treatment steps necessary to prepare high density PZT and PLZT. The microstructure and ferroelectric properties of the microwave processed materials were compared to conventionally sintered and fast fired PZT. Unique high density, small grain size, PZT and PLZT were obtained by microwave sintering either conventionally or fully microwave processed powders. It was estimated that microwave sintering would use only five percent of the energy used by conventional sintering.The suitability of microwave processing for the production of two modifications (Sr and La) of lead zirconate - lead titanate (PZT) ceramics was investigated in this program. A commercial microwave oven was used to evaluate drying, calcining, binder burnoff, and sintering. These materials were then compared to those produced by fast-firing and conventional sintering methods.

Convergent-bceam diffraction studies on lead zirconate titanate Ceramics

1986 ◽  
Vol 44 ◽  
pp. 482-483
Author(s):  
M.L.A. Dass ◽  
T.A. Bielicki ◽  
G. Thomas ◽  
T. Yamamoto ◽  
K. Okazaki
Keyword(s):  
Lead Zirconate Titanate ◽  
Direct Proof ◽  
Lead Zirconate ◽  
Subsolidus Phase ◽  
Pzt Ceramics ◽  
Subsolidus Phase Diagram ◽  
Zirconate Titanate ◽  
Two Phases ◽  
Cbd Method ◽  
Titanate Ceramics

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.

DISTRIBUTION OF HEXOSAMINE IN ELEGTROPHORETIC FRACTIONS OF AVIAN, BOVINE, PORCINE, AND HUMAN SERA

1967 ◽  
Vol 45 (4) ◽  
pp. 541-550 ◽  
Author(s):  
A. P. Gaunce ◽  
P. A. Anastassiadis
Keyword(s):  
Human Blood ◽  
Filter Paper ◽  
Cationic Resin ◽  
Human Sera ◽  
Hydrolysis Of ◽  
Direct Hydrolysis

The distribution of hexosamine among the proteins of avian, bovine, porcine, and human blood sera was studied by electrophoresis on filter paper. Hexosamine was determined after direct hydrolysis of stained sections of the paper, followed by chromatography of hydrolysates on cationic resin. Some substantial and statistically significant differences in hexosamine and protein contents of the zones were found among species.

A Fluorescence Polarization Assay for Cyclic Nucleotide Phosphodiesterases

2002 ◽  
Vol 7 (3) ◽  
pp. 215-222 ◽  
Author(s):  
Wei Huang ◽  
Yan Zhang ◽  
J. Richard Sportsman
Keyword(s):  
Cyclic Nucleotide ◽  
Fluorescence Polarization ◽  
Drug Targets ◽  
Second Messengers ◽  
Reaction Products ◽  
Cyclic Nucleotide Phosphodiesterases ◽  
Extracellular Signals ◽  
Fluorescence Polarization Assay ◽  
Hydrolysis Of ◽  
Nucleotide Phosphodiesterases

Cyclic nucleotide phosphodiesterases (PDEs) catalyze the hydrolysis of the 3′-ester bond of cyclic AMP (cAMP) and cyclic GMP (cGMP), important second messengers in the transduction of a variety of extracellular signals. There is growing interest in the study of PDEs as drug targets for novel therapeutics. We describe the development of a homogeneous fluorescence polarization assay for PDEs based on the strong binding of PDE reaction products (i.e., AMP or GMP) onto modified nanoparticles through interactions with immobilized trivalent metal cations. This assay technology (IMAP) is applicable to both cAMP- and cGMP-specific PDEs. Results of the assay in 384- and 1536-well microplates are presented.

scholarly journals Preparation, Structural, Electrical, and Ferroelectric Properties of Lead Niobate–Lead Zirconate–Lead Titanate Ternary System

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Rashmi Gupta ◽  
Seema Verma ◽  
Vishal Singh ◽  
K. K. Bamzai
Keyword(s):  
Dielectric Constant ◽  
Ternary System ◽  
Lead Titanate ◽  
Ac Conductivity ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Ternary Systems ◽  
Lead Zirconate ◽  
X Ray ◽  
Dispersive Nature

A ternary system of lead niobate–lead zirconate–lead titanate with composition xPN–yPZ–(x-y)PT where x=0.5 and y=0.15, 0.25, and 0.35 known as PNZT has been prepared by conventional mixed oxide route at a temperature of 1100°C. The formation of the perovskite phase was established by X-ray diffraction analysis. The surface morphology studied by scanning electron microscopy shows the formation of fairly dense grains and elemental composition was confirmed by energy dispersive X-ray analysis. Dielectric properties like dielectric constant and dielectric loss (ε′ and tan⁡δ) indicate poly-dispersive nature of the material. The temperature dependent dielectric constant (ε′) curve indicates relaxor behaviour with two dielectric anomalies. The poly-dispersive nature of the material was analysed by Cole-Cole plots. The activation energy follows the Arrhenius law and is found to decrease with increasing frequency for each composition. The frequency dependence of ac conductivity follows the universal power law. The ac conductivity analysis suggests that hopping of charge carriers among the localized sites is responsible for electrical conduction. The ferroelectric studies reveal that these ternary systems are soft ferroelectric.

scholarly journals Aqueous surface chemistry of gold mesh electrodes in a closed bipolar electrochemical cell

2020 ◽  
Vol 330 ◽  
pp. 135328 ◽  
Author(s):  
Alonso Gamero-Quijano ◽  
Grégoire Herzog ◽  
Micheál D. Scanlon
Keyword(s):  
Surface Chemistry ◽  
Electrochemical Cell ◽  
Aqueous Surface
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