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Barium titanate nanocomposite capacitor FY09 year end report

Stevens, Tyler E.; DiAntonio, Christopher D.; Winter, Michael R.; Chavez, Tom C.; Yang, Pin Y.; Roesler, Alexander R.

This late start RTBF project started the development of barium titanate (BTO)/glass nanocomposite capacitors for future and emerging energy storage applications. The long term goal of this work is to decrease the size, weight, and cost of ceramic capacitors while increasing their reliability. Ceramic-based nanocomposites have the potential to yield materials with enhanced permittivity, breakdown strength (BDS), and reduced strain, which can increase the energy density of capacitors and increase their shot life. Composites of BTO in glass will limit grain growth during device fabrication (preserving nanoparticle grain size and enhanced properties), resulting in devices with improved density, permittivity, BDS, and shot life. BTO will eliminate the issues associated with Pb toxicity and volatility as well as the variation in energy storage vs. temperature of PZT based devices. During the last six months of FY09 this work focused on developing syntheses for BTO nanoparticles and firing profiles for sintering BTO/glass composite capacitors.

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TYPE SAND Report YEAR 2009
OSTIDOI

Creating bulk nanocrystalline metal

Yang, Pin Y.; Hall, Aaron C.; Vogler, Tracy V.; Gill, David D.

Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

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TYPE SAND Report YEAR 2008
OSTIDOI

A beryllium dome specimen holder for XRD analysis of air sensitive materials

Powder Diffraction

Rodriguez, Marko A.; Boyle, Timothy J.; Yang, Pin Y.; Harris, Damon L.

A specially designed specimen holder employing a beryllium dome has been fabricated for collection of X-ray diffraction (XRD) data from highly reactive materials. The specimen holder has a robust O-ring type seal (< 10-9 Torr) and no observed intensity artifacts in the 1° to 150° 2θ range. The design also minimizes specimen displacement errors and allows for analysis of both powders and bulk specimens (i.e., pellets). The simple design makes for straightforward assembly of the holder within the confines of a glove box. XRD analysis of hygroscopic LaBr3 powders collected with this holder are suitable for Rietveld structure refinement, yielding unit cell lattice parameters of a=7.9703(6) Å and c=4.5122(6) Å cell volume= 248.44(6) Å3; Rp =7.70%. © 2008 International Centre for Diffraction Data.

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TYPE Conference YEAR 2008
ScopusOSTIDOI
Results 76–100 of 134
Results 76–100 of 134