bluuebunny/crossref_metadata_2025_split huggingface dataset:
Progress towards a low-cost commercial coated conductor
Authors: Annavarapu Suresh , Nguyen Nguyet , Cui Sky , Schoop Urs , Thieme Cees , Rupich Martin W. , Kodenkandath Thomas , Verebelyi Darren , Zhang Wei , Li Xiaoping , Li Qi , Paranthaman Mariappan , Goyal Amit , Cantoni Claudia , Kowalewski Matthew M. , List Fred A. 
Published: April 2011

ABSTRACTYBCO films prepared from metal trifluoroacetate (TFA) precursors on oxide-buffered textured non-magnetic substrates have achieved performance levels equaling that on oxide buffered textured Ni substrates. Critical current densities of 0.7 MA/cm2 to 1.0 MA/cm2 have been achieved in 0.4 µm thick YBCO films on short-length of CeO2/YSZ/Y2O3/Ni/Ni-13wt%Cr substrates. High-quality epitaxial buffers comprising a Ni layer, Y2O3 seed, YSZ barrier and CeO2 cap layers have been deposited over meter long tapes of deformation textured Ni and Ni-13%Cr using reel-to-reel processes. High-performance TFA-based YBCO films have been deposited on 0.1 m to 0.3 m lengths of these oxide buffered substrates using reel to reel processes. Critical current densities up to 1.0 MA/cm2 have been achieved in 0.4 µm thick YBCO films on CeO2/YSZ/Y2O3/Ni substrates. Using multiple coats of the metal trifluoroacetate precursors, thicker YBCO films have been demonstrated on oxide buffered substrates. Critical currents in excess of 100A/cm-width have been achieved for 1.2 µm -1.6 µm thick YBCO films on short lengths of CeO2/YSZ/Y2O3/Ni substrates.
How to Optimize Critical Current Performance of RE123 Materials by Controlling Oxygen Content
Authors: Shimoyama Jun-ichi , Horii Shigeru , Otzschi Kenji , Kishio Kohji 
Published: April 2011

ABSTRACTOxygen nonstoichiometry behaviors of REBa2Cu3Oy (RE123: RE= Nd, Sm, Eu, Gd, Dy. Ho and Y) compounds have been precisely determined by the thermogravimetric measurements. Dependence of oxygen content on temperature and oxygen partial pressure were found to slightly depend on the RE element. Thermodynamic quantities of oxygen, such as hO2 and sO2, also varied with RE element. Relationship between Tc and oxygen content is strongly dependent on the RE species. This suggests that pinnig effect due to the oxygen defects is different in each RE123 compound and, therefore, critical current properties of RE123 must be optimized by precise control of oxygen content as well as selection of suitable RE elements.
Phase Diagram Studies in the SrO-CuO-TiO2 System; Applications to YBCO Coated Conductors
Authors: Ayala A. , Holesinger T. G. , Peterson E. J. , Archuleta M. 
Published: April 2011

ABSTRACTSrTiO3 (STO) is a potential buffer layer material for use in YBa2Cu3Oy (YBCO) coated conductors based on the IBAD MgO process. However, the interactions with YBCO are not yet fully understood and little information exists in the way of phase diagrams. With this in mind, the tie-line between STO and SrCuO2 in the pseudo-ternary system SrO-CuO-TiO2 was investigated. Phase assemblages and compositions were determined by x-ray diffraction and electron microscopy in the temperature range of 1000°C to 1100°C in oxygen partial pressures of 1%, 10%, and 100%. Preliminary results showed that an appreciable amount of copper substitutes into the STO crystal structure. Conversely, Ti substitution into the SrCuO2 phase was not detected.
Thermoelectric Properties of Cd3−xAxTeO6 (A = In3+, La3+ and Bi3+) Ceramics
Authors: Luan Weiling , Shan Yue Jin , Itoh Mitsuru , Imoto Hideo 
Published: April 2011

ABSTRACTPerovskite oxide Cd3TeO6 was electron-doped by the introduction of oxygen vacancies and substitution of trivalent cations, In3+, La3+ and Bi3+. Their electric properties were investigated and compared with that of undoped Cd3TeO6. Negative temperature dependence of resistivity was observed in undoped, air-sintered Cd3TeO6. The resis tivity of Cd3−xAxTeO6 (A = In3+, La3+ and Bi3+) showed a metallic behavior with very slight temperature dependence. Indium-doped samples gave a low resistivity, which were decreased by more than three orders of magnitudes than that of air-sintered, undoped Cd3TeO6. The negative Seebeck coefficient and Hall coefficient obtained from all samples indicate that electrons are the charge carriers. The absolute Seebeck coefficients values of doped samples are decreased by 5 ∼ 10 times than that observed in undoped Cd3TeO6. Fortunately, the resistivity of indium-doped samples is low enough to provide a good thermoelectric power factor, and the optimum value of Cd2.97In0.03TeO6 was calculated as 1.35×10−4 Wm−1K−2. This result is close to that of the current best n-type perovskite thermoelectric material Ba0.4Sr0.6PbO3.
Large thermopower in metallic misfit cobalt oxides : improvement by cationic substitutions
Authors: Hébert S. , Wang L. B. , Maignan A. , Pelloquin D. , Hervieu M. , Raveau B. 
Published: April 2011

ABSTRACTThe thermoelectric properties of misfit cobaltites have been investigated. Their crystallographic structure consists in the stacking of layers of tilted CoO6 edge-shared octahedra, separated by rock-salt type layers. The Tl based family was first investigated : it is shown that by increasing the Tl content, the resistivity ρ can be reduced while keeping a large thermopower S. Another way to improve the figure of merit Z=S2/(ρκ) is to partially substitute Bi for Tl to increase S and keep a small ρ. A new family of Pb-based misfits has also been investigated. Two different techniques have been attempted to decrease ρ and/or increase S in this family : the partial substitution of Cu for Co, and the partial substitution of Ca for Sr.
Thermoelectric Properties of K2Bi8−xSbxSe13Solid Solutions and Se Doping
Authors: Kyratsi Theodora , Dyck Jeffrey S. , Chen Wei , Chung Duck-Young , Uher Ctirad , Paraskevopoulos Konstantinos M. , Kanatzidis Mercouri G. 
Published: April 2011

ABSTRACTOur efforts to improve the thermoelectric properties of β-K2Bi8Se13, led to systematic studies of solid solutions of the type β-K2Bi8−xSbxSe13. The charge transport properties and thermal conductivities were studied for selected members of the series. Lattice thermal conductivity decreases due to the mass fluctuation generated in the lattice by the mixed occupation of Sb and Bi atoms. Se excess as a dopant was found to increase the figure-of merit of the solid solutions.
133Cs and 23Na NMR Studies of Cs8NaxGe136 Clathrates
Authors: Marzke R.F. , Nolas G. S. , Gryko J. 
Published: April 2011

ABSTRACTWe report 133Cs and 23Na spectra of Cs8NaxGe136 clathrates. Fully loaded Cs8Na16Ge136 shows only ionic signals from both Cs and Na nuclei. In contrast to the Cs8Na16Si136 clathrate, germanium Cs8Na16Ge136 clathrate shows no large Knight or paramagnetic shifts. However, when sodium is removed from Cs8Na16Ge136, the resulting Cs8Ge136 clathrate shows a very large shift in the 133Cs NMR spectrum.
Novel Thermal Transport in Stable Binary Cd5.7Yb Quasicrystals
Authors: Pope A.L. , Tritt T.M. , Gagnon R. , Strom-Olsen J. 
Published: April 2011

ABSTRACTQuasicrystalline materials have been investigated for application as thermoelectric materials due to their inherently low thermal conductivity. With the discovery of a new stable, binary Cd5.7Yb quasicrystal, thermal and electrical transport measurements have been performed on these materials. It is found that the electronic contribution to the thermal conductivity calculated from the Wiedemann-Franz relationship is comparable to or greater than the total measured thermal conductivity, leaving the appearance of a “negligible lattice contribution.” In addition, no semblance of the lattice contribution appears in the temperature dependence of the thermal conductivity. The thermal conductivity increases linearly with temperature above 75K and proportional to T3/4 between 2 K and 75 K.
Effects of Porosity and Thermal Ageing on In-Plane Cracking Behavior of Thermal Barrier Coatings
Authors: Zhang Z. , Kameda J. , Swanson A. H. , Sakurai S. , Sato M. 
Published: April 2011

AbstractThis paper describes the effects of porosity and thermal ageing at 950°C for 4000 hr. in air on in-plane cracking behavior of plasma-sprayed thermal barrier coating (TBC) made up of 8 % yittria-stabilized zirconia. The in-plane TBC cracking was analyzed by a protruded TBC bend testing technique together with finite element stress analysis. As-deposited and aged TBC protruded specimens showed a large variation of porosity depending on the location of specimen extraction. The critical local tensile stress (s) necessary for the initiation of in-plane cracks for each specimen with different porosity was determined using elastic moduli (E) estimated from the porosity dependence of E. The s for in-plane cracking of the as-deposited TBC initially increased with increasing porosity and showed a peak when the porosity reached 0.23. It was shown that in-plane cracking at the interface of TBC and thermally grown oxides required much higher s than that at the interface of TBC and bond coatings. The thermal ageing led to a slight increase in s for away-from-interfacial TBC cracking. The dependence of in-plane TBC cracking behavior on the porosity is discussed in terms of effective critical stress via the Griffith criterion for porous materials.
Calcium Oxide Coating on Vanadium Alloys in Liquid Lithium
Authors: Park J.-H. , Natesan K. , Smith D. L. 
Published: April 2011

AbstractWe have fabricated CaO coatings on vanadium metal and various vanadium alloys (V-10Cr, V-1Ti, V-4Cr-4Ti, and V-5Cr-5Ti), for use in liquid metal blankets of fusion reactors. Initially, by monitoring weight change as a function of time, oxygen was charged into the vanadium alloys (rectangular sample, 2 x 1 x 0.1 cm) at 710°C by flowing Ar-O2gas. Oxygen-charged samples were exposed in 2.8 at.% Ca-Li at temperatures of 600 and 700°C for times between 50 and 120 h. The thickness of the in-situ-formed CaO was 13 to 30 m in the experimental conditions. Thicker CaO films were formed at higher oxygen contents and 700°C, while thinner CaO films were formed at lower oxygen contents and 600°C. The data show promise for in-situ formation of CaO layers on V alloys for the fusion blanket application.
On The Mechanism of Fatigue in Micron-Scale Structural Films of Polycrystalline Silicon
Authors: Muhlstein C. L. , Stach E. A. , Ritchie R. O. 
Published: April 2011

Abstract2-μm thick structural films of polycrystalline silicon are shown to display “metal-like” stress-life fatigue behavior in room air, with failures occurring after > 1011 cycles at stresses as low as half the fracture strength. Using in situ measurements of the specimen compliance and transmission electron microscopy to characterize such damage, the mechanism of thin-film silicon fatigue is deduced to be sequential oxidation and moisture-assisted cracking in the native SiO2 layer. This mechanism can also occur in bulk silicon but it is only relevant in thin films where the critical crack size for catastrophic failure can be exceeded within the oxide layer. The fatigue susceptibility of thin-film silicon is shown to be suppressed by alkene-based self-assembled monolayer coatings that prevent the formation of the native oxide.
Physical Properties and Diffusion Characteristics of CVD-Grown TiSiN Films
Authors: Anjum Dalaver , Dovidenko Katharine , Oktyabrsky Serge , Eisenbraun Eric , Kaloyeros Alain E. 
Published: April 2011

AbstractTiSiN films grown by chemical vapor deposition were characterized to evaluate the properties relevant to the application as a diffusion barrier in Cu-based interconnects. The films were grown using TiI4 + SiI4 + NH3 + H2 chemistry at substrate temperature, 370°C, and SiI4 - to-TiI4 precursor flow rate ratio of 30. The combined results from x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) revealed that the bulk of Ti32Si21N42 films were predominantly consisted of a mixture of cubic TiN and amorphous SiNx phases. The specific electrical resistivity of the films was about 2000 μΩcm which is a few times higher than that of sputtered TiSiN films having similar composition and thicknesses. The 40 nm-thick barrier appeared to be thermally stable against Cu diffusion at the annealing temperatures up to 550°C. Breakdown of this diffusion barrier occurred at 600°C and was accompanied by the formation of Cu3Si protrusions at the TiSiN/Si interface.
Field emission properties of nitrogen-doped diamond-like carbon films deposited by direct metal ion beam deposition
Authors: Song Kie Moon , Paik Namwoong , Kim Steven , Kim Daeil , Kim Seongjin , Kim Ju Youn , Jeon Hyeongtag 
Published: April 2011

AbstractNitrogen-doped diamond-like carbon (DLC) films were deposited on a silicon substrate by direct metal ion beam deposition (DMIBD). Partial pressures of nitrogen gas were changed to get different compositions of nitrogen in the DLC films. The composition and surface morphology of the films were examined using X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). Effect of nitrogen doping on field emission property was studied. The field emission data indicated that the nitrogen doping lowered the turn-on field and increase the current density. It was believed that doping of nitrogen into the DLC film plays an important role in enhancement of the field emission. This enhancement of field emission could be explained by the improvement of electron transport through nitrogen-dope DLC layer.
Nanoline Formation by Using Small-Aggregate Resist and Supercritical Resist Drying
Authors: Namatsu Hideo 
Published: April 2011

AbstractNanolines as small as 7 nm wide have been formed using a small-aggregate resist and supercritical resist drying. Aggregates consisting of resist polymers cause pattern roughness and cause nanolines to break. Hydrogen silsesquioxane (HSQ) is a resist material in which the aggregates are small due to its three-dimensional network. Development with an aqueous solution of TMAH provides high-contrast patterns. The problem that nanolines formed in HSQ collapse after development is solved by a supercritical resist drying technique. Supercritical drying suppresses the swelling of the resist by the rinse solution during development and thereby prevents nanolines from collapsing. The use of both small-aggregate HSQ resist and supercritical resist drying enables free-standing nanolines with a high aspect ratio to be formed without collapse.
New Photoresists with Photoacid Generator in the Backbone
Authors: Wu Hengpeng , Gonsalves Kenneth E. 
Published: April 2011

AbstractA photoacid generating (PAG) sulfonium monomer was designed and synthesized. CA resists were prepared based on this PAG monomer. Incorporation of the PAG in the resist backbone offered a few advantages such as high sensitivity and absence of phase separation. These resists proved to be especially useful for low-voltage EB lithography.
Plasmon Printing – a New Approach to Near-Field Lithography
Authors: Kik Pieter G. , Maier Stefan A. , Atwater Harry A. 
Published: April 2011

AbstractWe propose a method for replicating patterns with a resolution well below the diffraction limit, using broad beam illumination and standard photoresist. In particular it is shown that visible exposure (λ=410 nm) of silver nanoparticles in close proximity to a thin film of g-line resist (AZ 1813) can produce selectively exposed areas with a diameter smaller than λ/20. The technique relies on the local field enhancement around metal nanostructures when illuminated at the surface plasmon resonance frequency. The method can be extended to various metals, photosensitive layers, and particle shapes.
Scanning Tunneling Microscopy Observation Of Single Dangling Bonds on the Si(100)2×1:H Surface
Authors: Liu Lequn , Yu Jixin , Lyding Joseph W. 
Published: April 2011

AbstractThe electrical properties of single dangling bonds on the Si(100)2×1:H surface are investigated by ultra high vacuum scanning tunneling microscopy. On the N-type Si(100)2×1:H surface, single dangling bonds created by feedback controlled lithography and natural dangling bonds have a fixed negative charge. On the other hand, they are observed as neutral on the P-type Si(100)2×1:H surface. Current image tunneling spectroscopy is used to characterize both types of dangling bonds. The dangling bonds with fixed negative charge display a dramatic voltage dependence with Friedel oscillations observed in the empty state images. The neutral dangling bonds appear as protrusions in both the empty and filled state images.
Designing Photoresist Systems for Microlithography in Carbon Dioxide
Authors: Flowers Devin , Hoggan Erik , DeSimone Joseph M. , Carbonell Ruben 
Published: April 2011

AbstractCurrently, the microlithography industry creates large amounts of organic and aqueous wastes in the production of semiconductors. Using carbon dioxide can possibly eliminate the majority of these waste solvents as well as eliminate the image collapse problems shown with aqueous base development. We will discuss the use of carbon dioxide to replace the most solvent intensive steps of the microlithography process, spin coating, developing, and stripping. However, before CO2 can replace conventional solvents, photoresist systems must be designed and synthesized to be compatible with CO2. These photoresist systems must be soluble in liquid CO2 to insure that thin-uniform coatings can be produced by spin coating while maintaining characteristics of conventional resist systems such as low absorbance, high sensitivity, solubility contrast, good resolution, and etch resistance. Using our CO2 compatible resist system, we will demonstrate the ability of CO2 to spin coat uniform thin-films which (after exposing and PEB) can be developed using scCO2 to produce lithography features that may be stripped in CO2. Thus, revealing the enormous potential of CO2 to provide the microlithography industry an opportunity to escape its water and organic solvent dependence as it moves toward 157nm lithography.
Influence of The Dielectric on The Growth and Performance of Pentacene Thin Film Transistors
Authors: Knipp D. , Street R. A. , Krusor B. , Ho J. , Apte R. B. 
Published: April 2011

ABSTRACTThe electronic transport and the device properties of pentacene thin film transistors are reported, showing the influence of the dielectric on the structural and transport properties. The structure and morphology of pentacene films on organic and inorganic dielectrics were compared by x-ray diffraction measurements and atomic force microscopy. For the investigated dielectrics we observed a clear correlation between the morphology and the structural properties of the highly polycrystalline films. In the case of inorganic dielectrics the roughness of the dielectric has a distinct influence on the morphology and the structural properties, whereas the films on organic dielectrics bonding between pentacene and the dielectric may have an influence on the growth mechanism. We find that careful control of the deposition conditions give films with similar transport properties on organic and inorganic dielectrics. To study the electronic properties we have realized inverted staggered transistors. The TFTs exhibit mobilities of ∼0.4 cm2/Vs and on/off ratios of 108 on organic and inorganic dielectrics. The influence of the dielectric on the device mobility, threshold voltage and sub-threshold voltage slope are discussed.
Modeling of Channel Formation in Organic Field Effect Transistors
Authors: Li T. , Ruden P. P. , Campbell I. H. , Smith D. L. 
Published: April 2011

ABSTRACTWe report results of two-dimensional electrostatic modeling for (top-contact) organic field effect transistors, focusing on the formation of the conductive channel. The effect on channel formation of the choice of the source and drain contact metal is investigated. High work function metal (e.g., gold) source and drain contacts produce a conducting p-type region near these contacts. In contrast, low work function metal source and drain contacts (e.g., magnesium) lead to depleted regions. In the center of the device, between the source and drain contacts, the channel carrier density at a fixed gate bias is determined by the work function of the gate contact material, and is essentially independent of the metal used to form the source and drain contacts. The dependence of the transistor threshold voltage on the gate contact metal work function and the device implications of the spatial variation of the induced charge density are discussed.
Air Stable, Amorphous Organic Films and their Applications to Solution Processable Flexible Electronics
Authors: Veres Janos , Ogier Simon , Leeming Stephen , Brown Beverley , Cupertino Domenico 
Published: April 2011

ABSTRACTThe rapidly expanding field of organic semiconductors for display and low-cost electronic applications requires materials, which not only have high mobility but also benefit from solution processability and environmental stability. In this paper we present a new class of solution coatable organic materials with excellent stability to air and light. Spin-coated FET devices operate at ambient conditions without encapsulation and show p-type field-effect mobilities of 2 x 10-3 cm2V-1s-1 and on/off ratios greater than 104. Thin films can be deposited from common organic solvents onto a variety of substrates. These films are mechanically robust and can withstand temperatures in excess of 100 °C without significant changes in electrical performance. FET switching and transient characteristics at higher frequencies are also discussed. These types of materials should find applications in many areas of flexible electronics.
Investigation of Pu-Doped Ceramics Using Modified MCC-1 Leach Test
Authors: Nikolaeva Elena V. , Burakov Boris E. 
Published: April 2011

ABSTRACTLeach testing is an important tool for the investigation of chemical durability of radioactive waste forms. The data obtained from these tests allows for the selection of the most durable ceramics for the immobilization of weapons-grade plutonium. Ceramics based on cubic zirconia, (Zr,Gd,Pu)O2, doped with 10 wt.% 239Pu, zircon, (Zr,Pu)SiO4, doped with separately 5-6 and 10 wt.% 239Pu, pyrochlore, (Ca,Pu,Gd,Hf,U)2Ti2O7, doped with 10 wt.% 239Pu were studied using MCC-1 leach test. Ceramic samples were placed in test vessels with deionized water and set temperatures of 25°C and 90°C in an oven for 28 days. The leaching solution was removed and replaced with fresh deionized water after 3 and 14 days from the start of the test. Only data obtained after 14 and 28 days were used for the interpretation. No saturation of leach solution with Pu was observed in any experiments. It was found that the (without correction for porosity) normalized Pu mass loss (in g/m2 ) after 14 and 28 days was:- for the zirconia ceramic – 2 × 10−2 to 4 × 10−2 at 90°C and 8 × 10−3 to 9 × 10−3 at 25 °C;- for zircon doped with 5-6 wt.% of Pu – 7.0 × 10−3 to 8.2 × 10−3 at 90°C and 1.0 × 10−3 to 1.2 × 10−3 at 25 °C;- for zircon doped with 10 wt.% of Pu – 0.2 to 0.2 at 90°C and 3.0 × 10−2 to 4.0 × 10−2 at 25 °C;- for pyrochlore – 1.0 × 10−3 to 1.0 × 10−3 at 90°C and 2.0 × 10−3 to 3.0 × 10−3 at 25 °C.It was shown that the high leach rate for zircon based ceramic doped with 10 wt.% Pu was caused by the presence of the separated inclusions of PuO2 phases observed in ceramic matrix. The results obtained so far allow us to conclude that ceramics based on zircon, zirconia and pyrochlore are characterized by similar chemical resistance to leaching in deionized water. Based on its low porosity, zircon may be most durable ceramic host phase for Pu.