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

Description: 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: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of titanates, niobates, and tantalates to neutralized defense waste decontamination: materials properties, physical forms, and regeneration techniques. Final report

Description: A study of the application of sodium titanate (ST) to the decontamination of neutralized defense waste has been completed. The work was directed at Sr removal from dissolved salt cake, simulated in this work with a 6.0 N NaNO/sub 3/ - 0.6 N NaOH solution. Three physical forms of the titanates were developed including powder, pellets, and titanate-loaded resin beads and all were found to be superior to conventional organic ion exchange in this application. When spent, the titanate materials can … more
Date: January 1, 1981
Creator: Dosch, R. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Material selection for electrooptic deflectors

Description: 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: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transmission spectrum of lithium tantalate

Description: Measurement of absorbance along the z-axis of a lithium tantalate crystal was completed using a Cary spectrophotometer. Transmission through two polished but uncoated faces was about 62% which compares well with 73% calculated from Fresnel reflectivity equations. (FS)
Date: January 8, 1979
Creator: Hammond, P. R. & Spaeth, M. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Self-activating and doped tantalate phosphors.

Description: An ideal red phosphor for blue LEDs is one of the biggest challenges for the solid-state lighting industry. The appropriate phosphor material should have good adsorption and emission properties, good thermal and chemical stability, minimal thermal quenching, high quantum yield, and is preferably inexpensive and easy to fabricate. Tantalates possess many of these criteria, and lithium lanthanum tantalate materials warrant thorough investigation. In this study, we investigated red luminescence of… more
Date: January 1, 2011
Creator: Nyman, May Devan & Rohwer, Lauren Elizabeth Shea
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Shear horizontal surface acoustic wave microsensor for Class A viral and bacterial detection.

Description: The rapid autonomous detection of pathogenic microorganisms and bioagents by field deployable platforms is critical to human health and safety. To achieve a high level of sensitivity for fluidic detection applications, we have developed a 330 MHz Love wave acoustic biosensor on 36{sup o} YX Lithium Tantalate (LTO). Each die has four delay-line detection channels, permitting simultaneous measurement of multiple analytes or for parallel detection of single analyte containing samples. Crucial to o… more
Date: October 1, 2008
Creator: Branch, Darren W.; Huber, Dale L.; Brozik, Susan Marie & Edwards, Thayne L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Controller Synthesis of Metastable Oxides Utilizing Epitaxy and Epitaxial Stabilization

Description: Molecular beam epitaxy (MBE) has achieved unparalleled control in the integration of semiconductors at the nanometer. These advances were made through the use of epitaxy, epitaxial stabilization, and a combination of composition-control techniques including adsorption-controlled growth and RHEED-based composition control that we have developed, understood, and utilized for the growth of oxides. Also key was extensive characterization (utilizing RHEED, four-circle x-ray diffraction, AFM, TEM, an… more
Date: December 2, 2003
Creator: Schlom, Darrell
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Order-disorder behavior in KNbO{sub 3} and KNbO{sub 3}/KTaO{sub 3} solid solutions and superlattices by molecular-dynamics simulations.

Description: We use molecular-dynamics simulation to examine the order-disorder behavior in pure ferroelectric KNbO{sub 3} and in KNbO{sub 3}-KTaO{sub 3} ferroelectric-paraelectric solid solutions and superlattices. We find that the order-disorder behavior is remarkably robust and plays an important role in both the polarization rotation associated with switching of the perfect crystal and in the dynamical behavior of the solid solutions and superlattices.
Date: February 18, 2002
Creator: Phillpot, S. R.; Sepliarsky, M.; Streiffer, S. K.; Stachiotti, M. G. & Migoni, R. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microwave Processing for Advance Electro-Optic Materials

Description: This project addressed the technical and scientific goals of developing new methods for the formation of striation-free single crystals of potassium tantalate niobate. This solid-solution system has the potential for serving as a general electro-optic material with a wide range of optical applications. The performance of the material is, however, severely limited by the effects of compositional inhomogeneity that is generally induced during the single crystal growth process due to the nature of… more
Date: June 1, 2000
Creator: Boatner, L. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Transient Grating in a Knbo{Sub 3}/Ktao{Sub 3} Superlattice

Description: Time-resolved degenerate-four-wave-mixing (DFWM) techniques have been used to characterize the nonlinear optical response of a KNbO{sub 3}/KTaO{sub 3} superlattice grown by pulsed laser deposition on a 1 mm thick, (001)-oriented KTaO{sub 3} substrate. With a 30 psec pulsed laser, the difference in the nonlinear optical response between bulk KTaO{sub 3} and the superlattice was measured. Results indicate that a significant contribution to the response signal is due to the KNbO{sub 3} superlattic… more
Date: June 1, 1998
Creator: Liu, H.; Fernandez, F.; Jia, W. & Boatner, L. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Potassium dihydrogen phosphate and potassium tantalate niobate pyroelectric materials and far-infrared detectors

Description: This thesis discusses characterization of two ferroelectric materials and the fabrication of bolometers. Potassium tantalate niobate (KTN) and potassium dihydrogen phosphate (KDP) are chosen because they can be optimized for operation near 100K. Chap. 2 reviews the physics underlying pyroelectric materials and its subclass of ferroelectric materials. Aspects of pyroelectric detection are discussed in Chap. 3 including measurement circuit, noise sources, and effects of materials properties on py… more
Date: October 1, 1993
Creator: Baumann, H. B.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Radiation-disorder and Aperiodicity in Irradiated Ceramics. Final Technical Report, 22 June 1989--21 June 1992

Description: This final technical report documents the accomplishments of the program of research entitled ``Radiation Disorder and Aperiodicity in Irradiated Ceramics`` for the period June 22, 1989--June 21, 1992. This research forms the latest part on an on-going program, begun at MIT in 1983 under DOE support, which has had as its objectives investigation of the responses in radiation environments of ceramics heavily-irradiated with electrons, neutrons and ions, with potential applications to fusion ener… more
Date: July 1, 1992
Creator: Hobbs, L. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Radiation-disorder and Aperiodicity in Irradiated Ceramics

Description: This final technical report documents the accomplishments of the program of research entitled Radiation Disorder and Aperiodicity in Irradiated Ceramics'' for the period June 22, 1989--June 21, 1992. This research forms the latest part on an on-going program, begun at MIT in 1983 under DOE support, which has had as its objectives investigation of the responses in radiation environments of ceramics heavily-irradiated with electrons, neutrons and ions, with potential applications to fusion energy… more
Date: January 1, 1992
Creator: Hobbs, L.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The development of potassium tantalate niobate thin films for satellite-based pyroelectric detectors

Description: Potassium tantalate niobate (KTN) pyroelectric detectors are expected to provide detectivities, of 3.7 x 10{sup 11} cmHz {sup {1/2}}W{sup {minus}1} for satellite-based infrared detection at 90 K. The background limited detectivity for a room-temperature thermal detector is 1.8 x 10{sup 10} cmHz{sup {1/2}}W{sup {minus}1}. KTN is a unique ferroelectric for this application because of the ability to tailor the temperature of its pyroelectric response by adjusting its ratio of tantalum to niobium. … more
Date: May 1997
Creator: Cherry, H. B. B.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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The interpretation of HRTEM images of partially amorphized pyrochlore structure types

Description: Results of image simulations on partially amorphous microlite (Ca{sub 2}Ta{sub 2}O{sub 7}, pyrochlore structure) are presented. Results indicate that HRTEM images are not sensitive to position of amorphous layers within a crystalline matrix. It is also observed that the limit of detection of amorphous material within a crystalline matrix is dependent on total thickness. In thin crystals (<150{Angstrom}), up to 75 vol% crystalline material can give rise to aperiodic images, yet addition of a sma… more
Date: December 31, 1990
Creator: Miller, M. L. & Ewing, R. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effect of point defects and disorder on structural phase transitions

Description: Since the beginning in 1986, the object of this project has been Structural Phase Transitions (SPT) in real as opposed to ideal materials. The first stage of the study has been centered around the role of Point Defects in SPT`s. Our intent was to use the previous knowledge we had acquired in the study of point defects in non-transforming insulators and apply it to the study of point defects in insulators undergoing phase transitions. In non-transforming insulators, point defects, in low concent… more
Date: June 1, 1997
Creator: Toulouse, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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First principles study of substituents in KTaO{sub 3}

Description: The structural properties, energetics, and dynamics of Ca{sup 2+} and Mn{sup 2+} substituents in KTaO{sub 3} are investigated from first principles. It is found that Ca substitutes for both K and Ta ions. Oxygen vacancies bind to isolated Ca ions residing at Ta-sites, causing off-center Ca displacement and forming large dipoles. There is also evidence that oppositely charged defects may cluster together. The calculations predict that the activation energy for dipole reorientation via oxygen vac… more
Date: May 17, 2000
Creator: Leung, Kevin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Integration of electro-optic lenses and scanners on ferroelectric LiTaO{sub 3}

Description: An integrated electro-optic lens/scanner device was fabricated on a ferroelectric LiTaO{sub 3} wafer. This was done using lithographically defined domain-inverted regions extending through the crystal thickness. A lens power of 0.233 cm{sup {minus}1}kV{sup {minus}1} and a scanner deflection of 12.68 mrad{sup {minus}1}kV{sup {minus}1} was observed. The authors also demonstrate an electro-optic lens stack collimator which collimates an input beam focused to a 5{micro}m waist diameter at {minus}2.… more
Date: March 13, 1999
Creator: Gopalan, V.; Gahagan, K. T.; Jia, Q. X.; Tobinson, J. M.; Mitchell, T. E.; Schlesinger, T. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Pulsed laser deposition of epitaxial Sr(Ru{sub x}Sn{sub 1-x})O{sub 3} thin film electrodes and KNbO{sub 3}/Sr(Ru{sub x}Sn{sub 1-x})O{sub 3} bilayers

Description: Sr(Ru{sub x}Sn{sub 1-x}){sub 3} is proposed as a new conducting oxide for use in epitaxial multilayer structures. The Sr(Ru{sub o} {sub 48}Sn{sub 0.52})0{sub 3} composition exhibits an excellent lattice match with (100)-oriented KTaO{sub 3}, and films of this composition grown by pulsed laser deposition on KTaO{sub 3}, SrTiO{sub 3}, and LaAlO{sub 3} substrates have been analyzed by X-ray diffraction, Rutherford backscattering/ion channeling, and resistivity measurements. Epitaxial KNbO{sub 3}/S… more
Date: December 31, 1995
Creator: Christen, H. M.; Boatner, L. A.; English, L. Q.; Geea, L. A.; Marrero, P. J. & Norton, D. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Multi-watt 589nm fiber laser source

Description: We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichiometric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to &gt;15W using cladding pumped Nd{sup 3+} fiber amplifiers. The fiber amplifiers operate at 9… more
Date: January 19, 2006
Creator: Dawson, Jay W.; Drobshoff, Alex D.; Beach, Raymond J.; Messerly, Michael J.; Payne, Stephen A.; Brown, Aaron et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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