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Epitaxial Pb(Zr{sub 0.40}Ti{sub 0.60})O{sub 3}/SrRuO{sub 3} and PbTiO{sub 3}/SrRuO{sub 3} multilayer thin films prepared by MOCVD and rf sputtering

Description: Epitaxial SrRuO{sub 3} thin films were deposited by RF sputtering on SrTiO{sub 3} or MgO substrates for use as underlying electrodes. On these conductive substrates, epitaxial Pb(Zr{sub 0.35}Ti{sub 0.65})O{sub 3} (PZT) and PbTiO{sub 3} (PT) thin films were, deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), RBS channeling (RBS), transmission electron microscopy (TEM) and optical waveguiding were used to characterize phase, microstructure, defect structure, ref… more
Date: December 1, 1994
Creator: Foster, C. M.; Csencsits, R. & Baldo, P. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Growth, preparation, and dielectric properties of monodomain single crystal PbTiO{sub 3}

Description: A method is described for obtaining monodomain PbTiO{sub 3} single crystals with high electrical resistivity (10{sup 10}{Omega} cm) and low dielectric frequency dispersion. The single crystals of PbTiO{sub 3} were grown by flux solution method. Space charge related defects, which result in the large dielectric frequency dispersion, were eliminated by heat treatments. 90{degrees} domains were removed by applying a unidirectional compressive stress along the <100> crystallographic direction. The … more
Date: May 1, 1992
Creator: Li, Z.; Xu, X. Z.; Dai, X. H.; Lam, D. J. & Chan, S. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Synthesis and regeneration of lead (IV) acetate

Description: Lead acetate [Pb(O{sub 2}CMe){sub 4}] was easily synthesized from a warm solution of Pb{sub 3}O{sub 4}, HO{sub 2}CMe and O(OCMe){sub 2} following literature preparations when the appropriate measures to minimize water contamination were followed. Furthermore, Pb(O{sub 2}CMe){sub 4} which has been decomposed (evidenced by the appearance of a purple color due to oxidation) can be regenerated using a similar preparatory route. Introduction of Pb(O{sub 2}CMe){sub 4} from the two routes outlined abo… more
Date: November 1, 1996
Creator: Boyle, Timothy J.; Al-Shareef, Husam N. & Moore, Gregorio J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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BNL Building 650 lead decontamination and treatment feasibility study. Final report

Description: Lead has been used extensively at Brookhaven National Laboratory (BNL) for radiation shielding in numerous reactor, accelerator and other research programs. A large inventory of excess lead (estimated at 410,000 kg) in many shapes and sizes is currently being stored. Due to it`s toxicity, lead and soluble lead compounds are considered hazardous waste by the Environmental Protection Agency. Through use at BNL, some of the lead has become radioactive, either by contamination of the surface or thr… more
Date: October 1, 1995
Creator: Kalb, P. D.; Cowgill, M. G. & Milian, L. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Ultrafast Photovoltaic Response in Ferroelectric Nanolayers

Description: We show that light drives large-amplitude structural changes in thin films of the prototypical ferroelectric PbTiO3 via direct coupling to its intrinsic photovoltaic response. Using time-resolved x-ray scattering to visualize atomic displacements on femtosecond timescales, photoinduced changes in the unit-cell tetragonality are observed. These are driven by the motion of photogenerated free charges within the ferroelectric and can be simply explained by a model including both shift and screenin… more
Date: February 15, 2012
Creator: Daranciang, Dan
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Critical current density enhancement in rolled multifilament Bi-2223 HTS composites

Description: At 77 K and self-field, we report transport critical density (J{sub c}) of 58 kA/cm{sup 2} in rolled 19 and 85 filament Bi-2223 HTS tapes. For an 85-filament tape with transport J{sub c} of 50 kA/cm{sup 2}, transport J{sub c} of greater than 80 kA/cm{sup 2} electrical performance, increasing the number of the strong links between the 2223 colonies is believed to be the most important factor. Microstructure studies on these samples suggest that there is still great potential for further J{sub c}… more
Date: December 31, 1997
Creator: Li, Q.; Riley, G.N. Jr. & Parrella, R.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Evaluation of field enforced antiferroelectric to ferroelectric phase transition dielectrics and relaxor ferroelectrics for pulse discharge capacitors

Description: Discharge capacitors were designed based on materials with antiferroelectric (AFE) to ferroelectric (FE) field enforced transitions that had 10 times the capacitance of relaxor ferroelectric or state of the art BaTiO{sub 3} materials in the voltage range of interest. Nonlinear RLC circuit analysis was used to show that the AFE to FE materials have potentially more than 2 times the peak discharge current density capability of the BaTiO{sub 3} or lead magnesium niobate (PMN) based relaxor materia… more
Date: September 1, 1997
Creator: Hoover, B. D.; Tuttle, B. A.; Olson, W. R.; Goy, D. M.; Brooks, R. A. & King, C. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Physics in the fast lane: rotors, fast ions and mobile fermions

Description: Dynamic disorder in the high-temperature solid phases of the Zintl compounds CsPb and NaSn is characterized by. fast orientational motions of the polyanions and coupled motions of the cations Melting is characterized by slow translational motions of the centers of mass of the polyanions. The dynamic behavior of the ions is associated with dramatic increases in electrical conductivity characteristic of the behavior expected of a mixed conductor.
Date: September 1, 1996
Creator: Price, D.L. & Saboungi, M.-L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Research in Chemical Kinetics. Progress Report, July 20, 1988--August 30, 1989

Description: A major aspect of our research over the past decade under this contract has been the application of radioisotopes generated by nuclear reactions for the study of various kinetic mechanisms. Two general theoretical concepts have been explored in detail by this technique: (a) The addition of halogen atoms to olefins, which have been described for fifty years by the phrase {open_quotes}anti-Markownikoff{close_quotes} to indicate that the preference for one or the other end of an unsymmetric olefin… more
Date: September 1, 1996
Creator: Rowland, F. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Raman spectra of MOCVD-grown ferroelectric PbTiO{sub 3} thin films

Description: Lead titanate (PbTiO{sub 3}) has been grown on a variety of substrates by using the metalorganic chemical vapor deposition (MOCVD) technique. The substrates employed included Si, GaAs, MgO, fused-quartz, sapphire, and KTaO{sub 3}. Raman spectra from these heterostructures are presented. All of the films exhibited the strong, narrow spectral features characteristic of PbTiO{sub 3} perovskite-oxide crystals and indicative of high crystalline quality. The temperature behavior of the Raman modes, i… more
Date: December 31, 1993
Creator: Feng, Z. C.; Kwak, B. S.; Erbil, A. & Boatner, L. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Effects of Reactor Irradiation on the Thermoelectric Properties of Lead and Bismuth Tellurides

Description: Commercially available specimens of polycrystalline nand p-type lead telluride and n- and p-type bismuth telluride were irradiated in the Engineering Test Reactor. Total integrated flux times of 1.5 x 10/sup 20/ neutrons/cm/sup 2/ (thermal) and 1.6 x 10/sup 19/ neutrons/cm/sup 2/ (fast, i.e., for neutrons having energies greater than 1 (Mev) were accumulated by the specimens during irradiation. The specimen temperature during irradiation was 60 plus or minus 20 deg C. The effects of the irradia… more
Date: April 1, 1960
Creator: Corelli, J. C. & Frost, R. T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurements Through a Hot Cell Window Using Optical Tooling

Description: S>Optical tooling has been evaluated for the measurement of physical dimensions of radioactive parts through hot cell windows. Instruments were set up outside of a four foot thick lead glass window and by means of a grid plate which had been accurately scribed, a ''contour map'' or calibration chart of the window variations was recorded. Although the window was not specially selected, the readings were within 1.0% of the true dimension without using correction factors. One of the calibration ch… more
Date: July 18, 1958
Creator: Abbatiello, A. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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MOCVD growth and structure of PbTiO{sub 3} thin films

Description: PbTiO{sub 3} thin films grown on (001)MgO and (110)MgO by MOCVD have been characterized by x-ray diffraction and transmission electron microscopy. The PbTiO{sub 3} films deposited on (001)MgO under the optimum conditions always show a bi-layer structure. The top layer of the films near the free surface is c-axis oriented with the orientation relationship (001)[100]PbTiO{sub 3}{parallel}(001)[100]MgO. The bottom layer of the films near the substrate is a-axis oriented with (100)[001]PbTiO{sub 3}… more
Date: August 1, 1993
Creator: Gao, Y.; Bai, G.; Merkle, K. L.; Chang, H. L. M. & Lam, D. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ferroelectric domain structure of Pb(Zr /sub 52/Ti /sub 48/)O/sub 3/

Description: Ferroelectric domains are twins that are formed when PZT undergoes a phase transformation from a non-ferroelectric cubic phase to a ferroelectric tetragonal phase upon cooling below approx. 375/sup 0/C. The tetragonal phase is spontaneously polarized in the direction of c-axis, making each twin a ferroelectric domain.
Date: August 1, 1980
Creator: Goo, E.K. & Mishra, R.K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A FACILITY FOR THE STUDY OF THE EFFECTS OF NUCLEAR RADIATION ON MATERIALS

Description: The Sandia Engineering Reactor Facility consists of a 5-Mw light water moderated heterogeneous-type nuclear reactor, a large dry irradiation room and the necessary laboratory space for the preparation and post-irradiation testing of material samples. This Facility will be used to study the effects of radiation on the engineering properties of materials. Equipment for producing additional environments of heat, cold, altitude and vibration will be available for compounding with the radiation envi… more
Date: June 1, 1958
Creator: Colp, J L & Snyder, A W
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Polar intermetallic compounds of the silicon and arsenic family elements and their ternary hydrides and fluorides

Description: An investigation has been made on the effects of hydrogen and fluoride in the solid state chemistry of alkaline-earth and divalent rare-earth metal pnictide (Pn) and tetrelide (Tt) phases A{sub 5}(Pn,Tt,){sub 3}Z{sub x}, where A = Ca, Sr, Ba, Sm, Eu, Yb; Pn = As, Sb, Bi; Tt = Si, Ge, Sn, Pb and Z = H, F. Several trivalent rare-earth-metal pnictides, RE{sub 5}Pn{sub 3} (RE = Y, La, Gd, Tb, Dy, Ho, Er, Tm) and alkaline-earth-metal trielides, A{sub 5}Tr{sub 3}Z{sub x} (Tr = Ga, In, Tl) have been i… more
Date: October 17, 1996
Creator: Leon-Escamilla, E.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Epitaxial Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3}/SrRuO{sub 3} (x = 0, 0.35, 0.65) multilayer thin films on SrTiO{sub 3}(100) and MgO(100) prepared by MOCVD and RF sputtering

Description: Epitaxial SrRuO{sub 3} thin films were deposited on SrTiO{sub 3}(100) and MgO(100) substrates by RF sputtering for use as bottom electrodes and epitaxial buffer layers. On these conductive substrates, epitaxial Pb(Zr{sub x}Ti{sub 1{minus}x})O{sub 3} (PZT; x = 0.35,0.65) and PbTiO{sub 3} (PT; x = 0) thin films were deposited by metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD), RBS channeling (RBS), transmission electron microscopy (TEM) and optical waveguiding were used to… more
Date: February 1, 1995
Creator: Foster, C. M.; Csencsits, R.; Baldo, P. M.; Bai, G. R.; Li, Z.; Rehn, L. E. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)

Description: This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization. Tabs, figs, refs.
Date: May 1, 1993
Creator: Shum, S.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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A comparison of pressure compaction and diametral compression tests for determining granule strengths

Description: Lightning strikes can cause structural damage, ignite flammable materials, and produce circuit malfunctions in missiles, aircraft, and ground systems. Lightning arrestor connectors (LACs) are used to divert harmful lightning energy away from these systems by providing less destructive breakdown paths. Ceramic granules in the size range of 150--200 {micro}m are used in LACs to provide physical and electrical separation of contacts (pins) from the surrounding metal web, and to control the voltage… more
Date: December 31, 1994
Creator: Glass, S.J. & Newton, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Heavy ion irradiation of Bi-2223 silver-clad tapes for superconducting current density enhancement

Description: Silver-clad composite tapes of Bi(Pb)SrCaCuO-2223 were irradiated with 1 GeV Au{sup 23+} ions perpendicular to the tape plane, creating columnar tracks with 10 nm diameter. Detailed transmission electron microscopy shows continuous columns, but with variations in the track thickness of +/{minus}2 nm. Magnetic hystersis measurements show substantial enhancement of superconducting current density at most temperatures and fields. Granular and nongranular models for the origin of the magnetic signa… more
Date: July 1, 1993
Creator: Malozcnoff, A. P.; Carter, W. L.; Riley, G. N. Jr.; Wheeler, R. IV; Kirk, M. A.; Civale, L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Statistical Analysis of SNAP 10A Thermoelectric Converter Element Process Development Variables

Description: Statistical analysis, primarily analysis of variance, was applied to evaluate several factors involved in the development of suitable fabrication and processing techniques for the production of lead telluride thermoelectric elements for the SNAP 10A energy conversion system. The analysis methods are described as to their application for determining the effects of various processing steps, estabIishing the value of individual operations, and evaluating the significance of test results. The elimi… more
Date: December 15, 1962
Creator: Fitch, S. H. & Morris, J. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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