Showing papers on "Ferroelectric ceramics published in 1983"
TL;DR: In this paper, the temperature, microstructural and environmental variations of the fracture properties of ferroelectric ceramics are surveyed, showing that fracture toughness decreases on heating through the Curie temperature.
Abstract: This paper surveys the temperature, microstructural and environmental variations of the fracture properties of ferroelectric ceramics. Earlier work shows that fracture toughness decreases on heating through the Curie temperature. There is also anomalous behavior in the strength at small crack sizes, indicative of a grain size effect. Further, the strength properties are known to be adversely affected by the presence of water in the atmosphere. Data from recent indentation studies on barium titanate are used to investigate these phenomena.
63 citations
TL;DR: In this article, a modified ECAP computer program demonstrated that both the real and imaginary components of the impedance can be quantitatively described using the equivalent circuit models for the coupled individual grain resonances.
Abstract: It has often been suggested that the higher frequency dispersion (f∼107∼108 Hz) evident in the dielectric response of high-permittivity ferroelectric ceramics might be associated with piezoelectrically driven resonant mechanical motion of individual grains. The hypothesis certainly appears reasonable, but so far no direct verification appears to have been attempted. Our discovery that the individual crystallite resonances are well preserved in poled LiNbO3 bicrystals suggested that we explore the dispersion of LiNbO3 ceramics. In both conventionally sintered and uniaxially hot-pressed ceramics, the dielectric dispersion around 108 Hz has obvious resonant character. Using a modified ECAP computer program demonstrated that both the real and imaginary components of the impedance can be quantitatively described using the equivalent circuit models for the coupled individual grain resonances.
54 citations
TL;DR: The contribution of the bulk is calculated in this paper for the specific domain configuration in large grains which was revealed by etch patterns as mentioned in this paper, and the volume contribution is of the order of ervol ≈ 1000 whereas the measured values of er are about 1700.
Abstract: There is no simple experimental method which allows the separation of the dielectric constant in contributions of the bulk and those of 90°-domain wall motions The contribution of the bulk is calculated in this paper for the specific domain configuration in large grains which was revealed by etch patterns The volume contribution is of the order of ervol ≈ 1000 whereas the measured values of er are about 1700 Thus the domain wall contribution is of the order of 40% The slight increase of e33 with poling is caused by volume effects Domain wall contributions, however, support this increase at low polarizations
51 citations
TL;DR: In this paper, a beam intensity sensor has been fabricated with an interdigital electrode pattern on the surface using PbTiO3-0.9Pb(Mg 1/2W1/2)O3 solid solution.
Abstract: The bulk photovoltaic effect has been investigated in the ferroelectric PbTiO3-based and PLZT-family ceramics. The highest photovoltaic power (the photoelectric transducer efficiency of about 20 ppm) thus far obtained is in the 0.9PbTiO3-0. 1Pb(Mg1/2W1/2)O3 solid solution. Using this composition, a beam intensity sensor has been fabricated with an interdigital electrode pattern on the surface.
24 citations
Journal Article•
20 citations
TL;DR: In this paper, it was pointed out that the grain size effects on the transition parameters in ferroelectric ceramics can be explained on the basis of size effects of the constituent grains.
Abstract: It is pointed out that the grain size effects on the transition parameters in ferroelectric ceramics can be explained on the basis of size effects on the ferroelectric properties of the constituent grains.
19 citations
TL;DR: Satisfactory agreement between experimental results and theoretical calculations of waveexplosive energy conversion in cases of inductive, resistive and short circuit loads were obtained for a Pb(Zr97.5Ti2.5)O3+1wt%Nb2O5 PZT as discussed by the authors.
Abstract: Satisfactory agreement between experimental results and theoretical calculations of wave-explosive energy conversion in cases of inductive, resistive and short circuit loads were obtained for a Pb(Zr97.5Ti2.5)O3+1wt%Nb2O5 PZT.
17 citations
TL;DR: In this article, pyroelectric properties of bismuth layer-structured ferroelectrics (BLSF) were studied on their grain-oriented ceramics prepared by the hot-forging (H.F.) method.
Abstract: Pyroelectric properties of bismuth layer-structured ferroelectrics (BLSF) were studied on their grain-oriented ceramics prepared by the hot-forging (H.F.) method, as compared with ordinarily fired (O.F.) ones. The pyroelectric coefficient p was automatically measured and three figures of merit were calculated. Pyroelectric measurements using a chopped laser beam light gave the voltage responsivity Rv and the detectivity D* as a function of the chopping frequency. Figures of merit of H.F. ceramics are two times as large as those of O.F. ones. The H.F. ceramics have indicated the grain orientation effects on their pyroelectric properties.
15 citations
TL;DR: In this paper, a displacement laser interferometer system was used to determine the displacements of electrically excited specimens of piezoelectric and ferroelectric materials, and it was found that purely mechanical resonances can exist in these specimens independent of any detectable electrical disturbance.
12 citations
TL;DR: A displacement laser interferometer system has been adapted to measure the mechanical displacements of specimens of piezoelectric and ferroelectric materials driven by cyclic electric fields as mentioned in this paper.
Abstract: A displacement laser interferometer system has been adapted to measure the mechanical displacements of specimens of piezoelectric and ferroelectric materials driven by cyclic electric fields. It is found that mechanical resonances of quite large amplitudes can exist independent of any noticeable electrical disturbances. They are also detected in virgin and depoled specimens of ferroelectric ceramics. Preliminary experimental evidence suggests that this phenomenon depends on the domain structure of the ferroelectric materials.
11 citations
TL;DR: In this paper, the ferroelectric phase transition in PLZT was qualitatively explained on the basis of the theory of highly doped and compensated ferroelectrics, and the phase transition was shown to be reversible.
Abstract: The ferroelectric phase transition in PLZT is qualitatively explained on the basis of the theory of highly doped and compensated ferroelectrics.
TL;DR: In this article, the role of Manganese on properties of PbTiO3-like ferroelectric ceramics, ultrasonic, elastic, dielectric, and DC resistance characteristics have been measured before and after poling as a function of Mn-concentrations in the range from 0 to 4 mol% in Pb0.75 Ca 0.25)(Mg1/3 Nb2/3)0.0625 Ti0.9375)O3
Abstract: In order to confirm the role of Manganese on properties of PbTiO3-like ferroelectric ceramics, ultrasonic, elastic, dielectric, and DC resistance characteristics have been measured before and after poling as a function of Mn-concentrations in the range from 0 to 4 mol% in ferroelectric (Pb0.75 Ca0.25)((Mg1/3 Nb2/3)0.0625 Ti0.9375)O3 ceramics, in connection with the microstructures such as grain size and lattice constants. Observed results show that energy dissipation factors such as ultrasonic attenuation, dielectric loss, and DC resistance are markedly Mn-concentration sensitive.
01 Oct 1983
TL;DR: In this paper, the authors studied the dynamic loading and subsequent fragmentation of four different load zirconate titanate (95/5 PZT) ferroelectric ceramics using a torsional Kolsky bar apparatus.
Abstract: This paper studied the dynamic loading and subsequent fragmentation of four different load zirconate titanate (95/5 PZT) ferroelectric ceramics using a torsional Kolsky bar apparatus. Solid cylinders of the four materials were loaded in torsion at shear strain rates in the range 10/sup 2/ to 10/sup 3/s/sup -1/. Using the strain gage recordings of the incident, reflected and transmitted pulses, the energy required to fragment the specimen was determined for each test. In addition, the fragments resulting from each test were collected and analyzed by various technciques to determine their mass and size distributions. Results show some differences in particle distributions between the different batches of material. However, there is a more significant and consistent difference between the dynamic strength (as measured by the maximum shear stress) and the fragment mass distributions of the virgin material and the pressure depoled material, despite the fact that no differences were detected in the energy of fragmentation. Using earlier analytical results which relate the local kinetic energy of a potential fragment to the surface energy required to create that fragment, a relationship between the distribution of fragments from a test and material properties was derived. Results of tests on PZT as well asmore » other materials such as oil shale, graphite, uranium dioxide and glass indicate a good correlation between the fragment distribution parameter, n, and material properties as predicted by the theory. Finally, the results are analyzed to determine the potential effects of internal stresses on the dynamic strength of the material and its fragmentation characteristics.« less
TL;DR: A survey of theoretical and experimental studies of domain reorientation processes in ferroelectric ceramics under external mechanical stresses is presented in this paper, where theoretical models of orientational processes based on thermodynamic theory are considered.
Abstract: A survey of theoretical and experimental studies of domain reorientation processes in ferroelectric ceramics under external mechanical stresses is presented. Theoretical models of orientational processes based on thermodynamic theory are considered. It is demonstrated that distortion effects and phase-state change must be taken account of; their influence on orientational processes is shown. Kinetics of domain reorientations is investigated on the basis of an analysis of reversible and irreversible piezomodulus changes and of their time dependence. Relaxational processes of domain structure change and their effect on main properties of ferroelectric ceramics are discussed.
TL;DR: In this article, the PZT type of the ferroelectric ceramics is used for the construction of the new monolithic filter, which goes out of the phenomenon of the energy trapping of with-extensional vibrations in the thin piezoelectric strips that was first observed by Watanabe, Nakamura and Shimizu and described in the paper Ref. 1.
Abstract: The PZT type of the ferroelectric ceramics is used for the construction of the new monolithic filter. The design of the filter goes out of the phenomenon of the energy trapping of with-extensional vibrations in the thin piezoelectric strips that was first observed by Watanabe, Nakamura and Shimizu and described in the paper Ref. 1. The idea of the filter was briefly given in the paper Ref. 2.