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Magnitude Enhancement (magnitude + enhancement)
Selected AbstractsLow-Temperature Superionic Conductivity in Strained Yttria-Stabilized ZirconiaADVANCED FUNCTIONAL MATERIALS, Issue 13 2010Michael Sillassen Abstract Very high lateral ionic conductivities in epitaxial cubic yttria-stabilized zirconia (YSZ) synthesized on single-crystal SrTiO3 and MgO substrates by reactive direct current magnetron sputtering are reported. Superionic conductivities (i.e., ionic conductivities of the order ,1 ,,1cm,1) are observed at 500,°C for 58-nm-thick films on MgO. The results indicate a superposition of two parallel contributions , one due to bulk conductivity and one attributable to conduction along the film,substrate interface. Interfacial effects dominate the conductivity at low temperatures (<350,°C), showing more than three orders of magnitude enhancement compared to bulk YSZ. At higher temperatures, a more bulk-like conductivity is observed. The films have a negligible grain-boundary network, thus ruling out grain boundaries as a pathway for ionic conduction. The observed enhancement in lateral ionic conductivity is caused by a combination of misfit dislocation density and elastic strain in the interface. These very high ionic conductivities in the temperature range 150,500,°C are of great fundamental importance but may also be technologically relevant for low-temperature applications. [source] Use of Reversal Nanoimprinting of Nanoparticles to Prepare Flexible Waveguide Sensors Exhibiting Enhanced Scattering of the Surface Plasmon ResonanceADVANCED FUNCTIONAL MATERIALS, Issue 11 2010Dehui Wan Abstract A flexible surface plasmon resonance (SPR)-based scattering waveguide sensor is prepared by directly imprinting hollow gold nanoparticles (NPs) and solid gold NPs onto flexible polycarbonate (PC) plates,without any surface modification,using a modified reversal nanoimprint lithography technology. Controlling the imprinting conditions, including temperature and pressure, allows for the fine adjustment of the depths of the embedded metal NPs and their SPR properties. This patterning approach exhibits a resolution down to the submicrometer level. A 3D finite-difference time domain simulation is used to examine the optical behavior of light propagating parallel to the air/substrate interface within the near-field regime. Consistent with the simulations, almost an order of magnitude enhancement in the scattering signal after transferring the metal NPs from the glass mold to the PC substrate is obtained experimentally. The enhanced signal is attributed to the particles' strong scattering of the guiding-mode waves (within the waveguide) and the evanescent wave (above the waveguide) simultaneously. Finally, the imprinting conditions are optimized to obtain a strongly scattering bio/chemical waveguide sensor. [source] Chemical Vapor Deposition Repair of Graphene Oxide: A Route to Highly-Conductive Graphene MonolayersADVANCED MATERIALS, Issue 46 2009Vicente López Highly conductive chemically-derived graphene can be synthesized using an efficient two-step method starting from graphene oxide. The key strategy involves the use of a CVD process to heal defects contained within the monolayers, which imparts a two order of magnitude enhancement of electrical conductivity over the merely reduced samples. [source] Cu-Doped ZnO Nanowires for Efficient and Multispectral Photodetection Applications,ADVANCED MATERIALS, Issue 11 2008Nikolai Kouklin Cu-doped ZnO nanowires exhibiting high sensitivity to both UV and visible light are prepared by a vapor,liquid,solid method. The nanowires are highly resistive in the dark but exhibit several orders of magnitude enhancement in photoconductivity under UV and white-light irradiation because of an avalanche-type photocarrier multiplication effect, paving the way for their use in nanoscale photodetection applications. [source] | ||||||||||