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in subjects: "Zirconates"

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Theoretical aspects of solid state reactions in a mixed particulate ensemble and kinetics of lead zirconate formation

A theoretical analysis was carried out to estimate the quasi-steady-state external mass transport by lattice, surface and gaseous diffusion in terms of the stereologically measurable microstructural parameters of a mixed powder compact. It was shown that the gaseous transport can be described by a single dimensionless quantity termed sublimation transport modulus. Using these equations, the relative importance of the alternate external transport modes can be evaluated. Experimental work determi… more

Date: September 1, 1979

Creator: Chandratreya, S.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Ferroelectric ceramics for dielectric power conversion. Annual report, March 1, 1979-April 30, 1980

Materials selected for study were those which could be expected to have useful Curie temperatures, resistivities, coercive fields, and Devonshire coefficients. Materials studied include PZT (lead-zirconia-titania system), Bi(Na,K)Ti/sub 2/O/sub 6/, rare earth titanoniobates, other tantalates and niobates, and thin films. Graphs are given for spontaneous polarization as a function of composition, temperature dependence of spontaneous polarization and coercive field for modified PSZT dielectrics,… more

Date: May 1, 1980

Creator: Payne, D. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Investigations of the effect of the morphology of Nb dopant on lead zirconate ceramic

The microstructures of ferroelectric ceramics are a result of the dopants and of the many process variables associated with raw materials, powder processing, and ceramic firing. Metal ion substitutions of higher than normal valency are used as sintering aids to promote densification, to increase electrical resistivity, and to develop mature homogeneous microstructures with desirable piezoelectric and ferroelectric properties. Investigations are reported for the barium modified lead zirconate sy… more

Date: January 1, 1979

Creator: Keck, J. D. & Wilcox, P. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Boxcar photography

A simple, inexpensive diagnostic has been developed for time-resolved imaging of repetitive self-luminescent phenomena. An electro-optic birefringent ceramic shutter is employed to perform photographic sampling and yields time resolution of 100 ..mu..sec. Methods of image enhancement in the presence of background light from a finite-contrast shutter are discussed. The system has been applied to the study of plasma evolution in the CDX device. 21 refs., 4 figs.

Date: July 1, 1987

Creator: Greene, G. J.; Cutsogeorge, G. & Ono, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Oxygen permeability of several ceramic oxides above 1200 degrees C

Oxygen permeability as a function of temperature was measured for several ceramic oxides over the range 1200 to 1700{degrees}C. Of the oxides testbed, alumina, beryllia, yttria, lanthanum halfnate, and calcium zironcate exhibited the lowest permeabilities in order of decreasing resistance to oxygen transport. None of the permeability constants were less than the 10{sup {minus}10} to 10{sup {minus}12} g O{sub 2}/cm {center dot} s needed for a useful protective coating system above 1500{degrees}C… more

Date: January 1, 1992

Creator: Courtright, E.L. & Prater, J.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Develop techniques for ion implantation of PLZT (lead-lanthanum-zirconate-titanate) for adaptive optics

Research was conducted at Pacific Northwest Laboratory to develop high photosensitivity adaptive optical elements utilizing ion implanted lanthanum-doped lead-zirconate-titanate (PLZT). One centimeter square samples were prepared by implanting ferroelectric and anti-ferroelectric PLZT with a variety of species or combinations of species. These included Ne, O, Ni, Ne/Cr, Ne/Al, Ne/Ni, Ne/O, and Ni/O, at a variety of energies and fluences. An indium-tin oxide (ITO) electrode coating was designed … more

Date: July 1, 1987

Creator: Batishko, C. R.; Brimhall, J. L.; Pawlewicz, W. T.; Stahl, K. A. & Toburen, L. H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Photosensitivity enhancement of PLZT ceramics by positive-ion implantation

The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and nonvolatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Implanted ions include H/sup +/, He/sup +/, Ne/sup +/, Ar/sup +/, as well as chemically reactive ions from Fe, Cr, and Al. The positive ion implantation advantageously serves to shift the absorption characteristics of the P… more

Date: January 28, 1982

Creator: Peercy, P.S. & Land, C.E.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

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Evaluation of ceramic and polymeric materials for use in engineered barrier systems

Ceramic materials evaluated in the screening studies were Al/sub 2/O/sub 3/ (99.8%), mullite, vitreous silica, BaTiO/sub 3/, CaTiO/sub 3/, CaZrO/sub 3/, CaTiSiO/sub 5/, TiO/sub 2/, ZrSiO/sub 4/, basalt, Pyroceram 9617, and Marcor code 9658 machinable glass ceramic. One grade of graphite (Toyotanso IB-11) was also evaluated. Demineralized water, a synthetic Hanford groundwater, and a synthetic NaCl brine solution were used in the screening tests. Demineralized water was used in all five of the l… more

Date: January 1, 1980

Creator: Fullam, H.T. & Skiens, W.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Material selection for electrooptic deflectors

The selection of a material for a practical device is generally guided by a number of criteria, including cost, size, difficulty of fabrication, durability, driver requirements, and system constraints. A quantitative analysis can usually be made for comparison, or a figure of merit can be computed. In the case of materials for electrooptical (EO) devices the choice is often made based on the availability of materials meeting some minimum system requirement. For fast EO deflectors, where a large… more

Date: September 1, 1988

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Properties and Characterization of Thin Film Ferroelectric Capacitors for Nonvolatile Memories

Thin film ferroelectric materials are the basis for a new, promising IC nonvolatile memory technology. The primary material being studied for ferroelectric memories is PZT. One of the key factors in determining the feasibility of PZT ferroelectric memories for weapon or space applications is whether PZT ferroelectric technology can be integrated into a radiation-hardened CMOS or bipolar process. Sandia National Laboratories has a program to study ferroelectric/CMOS process integration issues. T… more

Date: January 1, 1990

Creator: Nasby, R. D.; Schwank, J. R.; Rodgers, M. S.; Miller, S. L.; Tuttle, B. A.; Liang, A. Y. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Role of Structure in Ion Movement of Glasses Progress Report

Three kinds of experiments were performed: modified random network model and ion movement; role of melt structure in ion transport in glassy state; and ion movement in fluorozirconate glass (breakdown of correspondence between electrical and nuclear spin relaxation). A comment is offered on dielectric loss peak in glasses. 11 refs, 1 fig. (DLC)

Date: November 3, 1992

Creator: Jain, Himanshu

Item Type: Report

Partner: UNT Libraries Government Documents Department

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A first-principles density functional theory study of the electronic structural and thermodynamic properties of M2ZrO3 and M2CO3 (M=Na, K) and their capabilities for CO2 capture

Alkali metal zirconates could be used as solid sorbents for CO{sub 2} capture. The structural, electronic, and phonon properties of Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3} are investigated by combining the density functional theory with lattice phonon dynamics. The thermodynamics of CO{sub 2} absorption/desorption reactions of these two zirconates are analyzed. The calculated results show that their optimized structures are in a good agreement with exp… more

Date: 2012

Creator: Duan, Yuhua

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Research and development to overcome fouling of membranes

During this first year of the program, we have successfully accomplished the main objective of demonstrating the feasibility of using piezoelectrically assisted ultrafiltration to reduce membrane fouling and enhance the flux through ultrafiltration membranes. A preliminary economic evaluation, accounting for the power consumption of the piezoelectric driver and the extent of permeate flow rate enhancement, has also shown that piezoelectrically assisted ultrafiltration is cost effective and econ… more

Date: June 1, 1992

Creator: Narang, S. C.; Sharma, S. K.; Ventura, S. C.; Roberts, D. L. & Ahner, N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ELECTRON MICROSCOPY STUDY OF THE FERROELECTRIC DOMAINS AND DOMAIN WALL STRUCTURE IN Pb.52Ti.48O3

The crystallography of the domains and domain walls in PZT are studied using electron diffraction and transmission electron microscopy. Both 90{sup o} and 180{sup o} domains are observed and the 90{sup o} domains are shown to be deformation twins with displacement along <110> on {l_brace}110{r_brace}. The thickness of the 90{sup o} domain wall is determined to be {approx}< 100 {angstrom}. Leadon Zirconate Titanate (PZT) is a ferroelectric material at room temperature and it is used ext… more

Date: August 1, 1980

Creator: Goo, E.K.W.; Mishra, R.K. & Thomas, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Oxalate co-precipitation synthesis of calcium zirconate and calcium titanate powders.

Fine powders of calcium zirconate (CaZrO{sub 3}, CZ) and calcium titanate (CaTiO{sub 3}, CT) were synthesized using a nonaqueous oxalate co-precipitation route from Ca(NO{sub 3}){sub 2}{center_dot}4 H{sub 2}O and group(IV) n-butoxides (Ti(OBu{sup n}){sub 4} or Zr(OBu{sup n}){sub 4}). Several reaction conditions and batch sizes (2-35 g) were explored to determine their influence on final particle size, morphology, and phase. Characterization of the as-prepared oxalate precursors, oven dried oxal… more

Date: June 1, 2009

Creator: Hernandez-Sanchez, Bernadette A. & Tuttle, Bruce Andrew

Item Type: Report

Partner: UNT Libraries Government Documents Department

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APPLICATION OF MECHANICAL ACTIVATION TO PRODUCTION OF PYROCHLORE CERAMIC CONTAINING SIMULATED RARE-EARTH ACTINIDE FRACTION OF HLW

Samples of zirconate pyrochlore ceramic (REE)2(Zr,U)2O7 (REE = La-Gd) containing simulated REE-An fraction of HLW were synthesized by two routes: (1) conventional cold compaction of oxide mixtures in pellets under pressure of 200 MPa and sintering of the pellets at 1550 C for 24 hours; and (2) using preliminary mechanical activation of oxide powders in a linear inductive rotator (LIV-0.5E) and a planetary mill - activator with hydrostatic yokes (AGO-2U) for 5 or 10 min. All the samples sintered… more

Date: February 27, 2003

Creator: Stefanovsky, S. V.; Kirjanova, O. I.; Chizhevskaya, S. V.; Yudintsev, S. V. & Nikonov, B. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ion-implanted PLZT ceramics: a new high-sensitivity image storage medium

Results were presented of our studies of photoferroelectric (PFE) image storage in H- and He-ion implanted PLZT (lead lanthanum zirconate titanate) ceramics which demonstrate that the photosensitivity of PLZT can be significantly increased by ion implantation in the ceramic surface to be exposed to image light. More recently, implantations of Ar and Ar + Ne into the PLZT surface have produced much greater photosensitivity enhancement. For example, the photosensitivity after implantation with 1.… more

Date: January 1, 1980

Creator: Peercy, P.S. & Land, C.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Oxygen permeability of several ceramic oxides above 1200{degrees}C

Oxygen permeability as a function of temperature was measured for several ceramic oxides over the range 1200 to 1700{degrees}C. Of the oxides testbed, alumina, beryllia, yttria, lanthanum halfnate, and calcium zironcate exhibited the lowest permeabilities in order of decreasing resistance to oxygen transport. None of the permeability constants were less than the 10{sup {minus}10} to 10{sup {minus}12} g O{sub 2}/cm {center_dot} s needed for a useful protective coating system above 1500{degrees}C… more

Date: January 1, 1992

Creator: Courtright, E. L. & Prater, J. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Influence of porosity on the mechanical properties of lead zirconate--titanate ceramics

Niobium doped lead zirconate-titanate (PNZT) was used to investigate the effect of porosity on the mechanical properties of a polycrystalline ceramic. Spherical and acicular pores (25 to 150 ..mu..m) were introduced by using organic materials and the grain size (2 to 5 ..mu..m) was constant throughout the study. The very fine pores (2 to 3 ..mu..m) were formed by varying the sintering conditions and the grain size was comparable to the pore size. The fracture strength of the ceramic was measure… more

Date: September 1, 1976

Creator: Biswas, D. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Role of structure in ion movement of glasses. Progress report, January 5, 1992--November 1, 1992

Date: November 3, 1992

Creator: Jain, Himanshu

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Plant Line Trial Evaluation of Viable Non-Chromium Passivation Systems for Electrolytin Tinplate, ETP (TRP 9911)

Plant trial evaluations have been completed for two zirconium-based, non-chromium passivation systems previously identified as possible alternatives to cathodic dichromate (CDC) passivation for electrolytic tinplate (ETP). These trials were done on a commercial electrolytic tin plating line at Weirton Steel and extensive evaluations of the materials resulting from these trials have been completed. All this was accomplished as a collaborative effort under the AISI Technology Roadmap Program and … more

Date: June 30, 2003

Creator: Sinsel, John A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Novel Inorganic Membranes for High Temperature Carbon Dioxide Separation: Final Technical Report

We studied feasibility of two types of dense inorganic membranes which are fundamentally different from those porous inorganic membranes reported in the literature for separation of carbon dioxide from gas streams at high temperatures. The first is a symmetric, dense membrane made of Li{sub 2}ZrO{sub 3} and the second is a dual-phase metal-carbonate membrane. We have identified a unique CO{sub 2} sorption/desorption mechanism on lithium zirconate. Considering the all obtained data, we proposed … more

Date: February 1, 2003

Creator: Lin, Jerry Y. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Mechanical properties of porous PNZT polycrystalline ceramics

Niobium-doped lead zirconate-titanate (PNZT) was used to investigate the effect of porosity on the mechanical properties of a polycrystalline ceramic. Spherical pores (110 to 150 ..mu..m diameter) were introduced by using organic materials in the initial specimen fabrication. The matrix grain size (2 to 5 ..mu..m) was kept constant. Small pores (2 to 3 ..mu..m diameter) of the order of the grain size were formed by varying the sintering conditions. The effect of porosity on strength was predict… more

Date: August 1, 1977

Creator: Biswas, Dipak R. & Fulrath, Richard M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Electrooptic shutter devices utilizing PLZT ceramic wafers

Optical transparency was achieved in lead zirconate-titanate ferroelectric ceramics by substituting moderate amounts of the element lanthanum (8 to 12%) for lead. These compositions exhibit the quadratic (Kerr) electrooptic effect. The excellent optical qualities of these materials (designated PLZT) has permitted the practical utilization of their electrooptic properties in a number of devices. All of these devices utilize the classic Kerr cell arrangement. A PLZT wafer with optical axis orient… more

Date: January 1, 1981

Creator: Thornton, Allen L.

Item Type: Article

Partner: UNT Libraries Government Documents Department