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Articles 145951 - 145980 of 302581

Full-Text Articles in Physical Sciences and Mathematics

Search For Physics Beyond The Standard Model In Events With Two Leptons, Jets, And Missing Transverse Momentum In Pp Collisions At √S= 8 Tev, Vardan Khachatryan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva, The Cms Collaboration Jan 2015

Search For Physics Beyond The Standard Model In Events With Two Leptons, Jets, And Missing Transverse Momentum In Pp Collisions At √S= 8 Tev, Vardan Khachatryan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva, The Cms Collaboration

Aerospace, Physics, and Space Science Faculty Publications

A search is presented for physics beyond the standard model in final states with two opposite-sign same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 19.4 fb−1 of proton-proton collisions at √S= 8 TeV collected with the CMS detector at the CERN LHC in 2012. The analysis focuses on searches for a kinematic edge in the invariant mass distribution of the oppositesign same-flavor lepton pair and for final states with an on-shell Z boson. The observations are consistent with expectations from standard model processes and are interpreted in terms of upper limits on …

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Erratum To: Search For New Physics In Events With Same-Sign Dileptons And Jets In Pp Collisions At S√ = 8 Tev, The Cms Collaboration, S. Chatrchyan, V. Khachatryan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva Jan 2015

Erratum To: Search For New Physics In Events With Same-Sign Dileptons And Jets In Pp Collisions At S√ = 8 Tev, The Cms Collaboration, S. Chatrchyan, V. Khachatryan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

We update the parameters of the fitted functions for lepton and jet selection efficiencies presented in section 9 of the original paper. Due to an editorial error, these numbers were wrongly inserted. The corresponding figures, figures 10 and 11 of the original paper, showing the fitted functions, are unchanged.

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Measurement Of The Ratio Of The Production Cross Sections Times Branching Fractions Of B ± C  → J/Ψπ ± And B± → J/Ψk ± And B(B±C→J/Ψπ±Π±Π∓)/B(B±C→J/Ψπ±) In Pp Collisions At S√=7 Tev, The Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva Jan 2015

Measurement Of The Ratio Of The Production Cross Sections Times Branching Fractions Of B ± C  → J/Ψπ ± And B± → J/Ψk ± And B(B±C→J/Ψπ±Π±Π∓)/B(B±C→J/Ψπ±) In Pp Collisions At S√=7 Tev, The Cms Collaboration, V. Khachatryan, A. M. Sirunyan, Marc M. Baarmand, Marcus Hohlmann, Himali Kalakhety, Francisco Yumiceva

Aerospace, Physics, and Space Science Faculty Publications

The ratio of the production cross sections times branching fractions (σ(B±c)B(B±c→J/ψπ±))/(σ(B±)B(B±→J/ψK±)) is studied in proton-proton collisions at a center of-mass energy of 7 TeV with the CMS detector at the LHC. The kinematic region investigated requires B c ± and B± mesons with transverse momentum p T > 15 GeV and rapidity |y|< 1.6. The data sample corresponds to an integrated luminosity of 5.1 fb-1. The ratio is determined to be [0.48±0.05(stat)± 0.03(syst)±0.05 (τBc)]%. The B c ± → J/ψπ ± π ± π ∓ decay is …

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Systematic Study Of Azimuthal Anisotropy In Cu + Cu And Au + Au Collisions At √Snn =62.4 And 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration Jan 2015

Systematic Study Of Azimuthal Anisotropy In Cu + Cu And Au + Au Collisions At √Snn =62.4 And 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration

Aerospace, Physics, and Space Science Faculty Publications

We have studied the dependence of azimuthal anisotropy v₂ for inclusive and identified charged hadrons in Au+Au and Cu+Cu collisions on collision energy, species, and centrality. The values of v₂ as a function of transverse momentum pT and centrality in Au+Au collisions at sNN=200 and 62.4 GeV are the same within uncertainties. However, in Cu+Cu collisions we observe a decrease in v₂ values as the collision energy is reduced from 200 to 62.4 GeV. The decrease is larger in the more peripheral collisions. By examining both Au+Au and Cu+Cu collisions we find that v₂ depends both on eccentricity and the …

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The Game Chromatic Number Of Trees And Forests, Charles Dunn, Victor Larsen, Troy Retter, Kira Lindke, Dustin Toci Jan 2015

The Game Chromatic Number Of Trees And Forests, Charles Dunn, Victor Larsen, Troy Retter, Kira Lindke, Dustin Toci

Faculty Publications

While the game chromatic number of a forest is known to be at most 4, no simple criteria are known for determining the game chromatic number of a forest. We first state necessary and sufficient conditions for forests with game chromatic number 2 and then investigate the differences between forests with game chromatic number 3 and 4. In doing so, we present a minimal example of a forest with game chromatic number 4, criteria for determining in polynomial time the game chromatic number of a forest without vertices of degree 3, and an example of a forest with maximum degree …

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The Relaxed Edge-Coloring Game And K-Degenerate Graphs, Charles Dunn, David Morawski, Jennifer Firkins Nordstrom Jan 2015

The Relaxed Edge-Coloring Game And K-Degenerate Graphs, Charles Dunn, David Morawski, Jennifer Firkins Nordstrom

Faculty Publications

The (r, d)-relaxed edge-coloring game is a two-player game using r colors played on the edge set of a graph G. We consider this game on forests and more generally, on k-degenerate graphs. If F is a forest with ∆(F) = ∆, then the first player, Alice, has a winning strategy for this game with r = ∆ − j and d ≥ 2j + 2 for 0 ≤ j ≤ ∆ − 1. This both improves and generalizes the result for trees in [10]. More broadly, we generalize the main result in [10] …

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Effect Of Tensile Load On The Actuation Performance Of Ph-Sensitive Hydrogels, Sina Naficy, Geoffrey M. Spinks Jan 2015

Effect Of Tensile Load On The Actuation Performance Of Ph-Sensitive Hydrogels, Sina Naficy, Geoffrey M. Spinks

Australian Institute for Innovative Materials - Papers

pH-responsive hydrogels are capable of converting chemical energy to mechanical work. To optimize their use as actuators, their response when operating against an external load must be fully characterized. Here, the actuation strain of a model pH-sensitive hydrogel as a function of different constant loads is studied. The experimental actuation strain, produced by switching the pH from 2 to 12, decreases significantly and monotonically with increasing initial tensile load. Two models are developed to predict the actuation strain as a function of applied stress. Simple mechanical models based on the change in hydrogel modulus and cross sectional area due to …

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Size-Dependent Chemical Reactivity Of Silicon Nanocrystals With Water And Oxygen, Melanie L. Mastronardi, Kenneth K. Chen, Kristine Liao, Gilberto Casillas, Geoffrey A. Ozin Jan 2015

Size-Dependent Chemical Reactivity Of Silicon Nanocrystals With Water And Oxygen, Melanie L. Mastronardi, Kenneth K. Chen, Kristine Liao, Gilberto Casillas, Geoffrey A. Ozin

Australian Institute for Innovative Materials - Papers

A detailed investigation examines how the size of allylbenzene-capped silicon nanocrystals (ncSi:AB) affects their chemical reactivity with gaseous O2, H2O, and O2/H2O as probed by in situ luminescence spectroscopy. Specifically, changes in the photoluminescence (PL) of size-separated ncSi:AB are monitored through alterations of their PL absolute quantum yield (AQY) as well as the wavelength and intensity of their PL spectra over time. These experiments, conducted under both continuous and intermittent illumination, help elucidate the roles of O2, H2O, and mixtures of O2/H2O, with respect …

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A Custom Battery For Operando Neutron Powder Diffraction Studies Of Electrode Structure, Wei Kong Pang, Vanessa Peterson Jan 2015

A Custom Battery For Operando Neutron Powder Diffraction Studies Of Electrode Structure, Wei Kong Pang, Vanessa Peterson

Australian Institute for Innovative Materials - Papers

Structure-property relations are central to understanding functional materials, and for battery research the use of neutron powder diffraction to reveal the atomistic and molecular-scale origin of battery performance characteristics is often essential. Although operando experiments of this kind are increasingly common as neutron sources and instrumentation advance, these experiments are hindered by the often large barrier presented by the preparation of whole batteries that yield a neutron diffraction signal from the electrode of interest that is sufficient to extract detailed structural information. This article presents a custom battery that is specifically designed for operando neutron powder diffraction. The battery is …

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A Facile Approach To Synthesize Stable Cnts@Mno Electrocatalyst For High Energy Lithium Oxygen Batteries, Wenbin Luo, Shulei Chou, Jiazhao Wang, Yu-Chun Zhai, Hua-Kun Liu Jan 2015

A Facile Approach To Synthesize Stable Cnts@Mno Electrocatalyst For High Energy Lithium Oxygen Batteries, Wenbin Luo, Shulei Chou, Jiazhao Wang, Yu-Chun Zhai, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

A composite of manganese monoxide loaded onto carbon nanotubes (CNTs@MnO) has been synthesized by a facile approach, in which the CNTs form a continuous conductive network connecting the electrocatalyst MnO nanoparticles together to facilitate good electrochemical performance. The electrocatalyst MnO shows favourable rechargeability, and good phase and morphology stability in lithium oxygen batteries. Excellent cycling performance is also demonstrated, in which the terminal voltage is higher than 2.4 V after 100 cycles at 0.4 mA cm-2, with 1000 mAh g-1 (composite) capacity. Therefore, this hybrid material is promising for use as a cathode material for lithium oxygen …

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Flexible Free-Standing Graphene Paper With Interconnected Porous Structure For Energy Storage, Kewei Shu, Caiyun Wang, Sha Li, Chen Zhao, Yang Yang, Hua-Kun Liu, Gordon G. Wallace Jan 2015

Flexible Free-Standing Graphene Paper With Interconnected Porous Structure For Energy Storage, Kewei Shu, Caiyun Wang, Sha Li, Chen Zhao, Yang Yang, Hua-Kun Liu, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

A novel porous graphene paper is prepared via freeze drying a wet graphene oxide gel, followed by thermal and chemical reduction. The macroscopic structure of the formed graphene paper can be tuned by the water content in the gel precursor. With 92% water content, an interconnected macroporous network can be formed. This porous graphene (PG) paper exhibits excellent electrochemical properties. It can deliver a high discharge capacity of 420 mA h g−1 at a current density of 2000 mA g−1 when used as binder-free lithium ion battery anode. PG paper exhibits a specific capacitance of 137 F g …

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Controllable Synthesis Of Concave Cubic Gold Core-Shell Nanoparticles For Plasmon-Enhanced Photon Harvesting, Yang Bai, Teera Butburee, Hua Yu, Zhen Li, Rose Amal, Gao Qing (Max) Lu, Lianzhou Wang Jan 2015

Controllable Synthesis Of Concave Cubic Gold Core-Shell Nanoparticles For Plasmon-Enhanced Photon Harvesting, Yang Bai, Teera Butburee, Hua Yu, Zhen Li, Rose Amal, Gao Qing (Max) Lu, Lianzhou Wang

Australian Institute for Innovative Materials - Papers

Well-defined core-shell nanoparticles (NPs) containing concave cubic Au cores and TiO2 shells (CA@T) were synthesized in colloidal suspension. These CA@T NPs exhibit Localized Surface Plasmon Resonance (LSPR) absorption in the NIR region, which provides a unique property for utilizing the low energy range of the solar spectrum. In order to evaluate the plasmonic enhancement effect, a variety of CA@T NPs were incorporated into working electrodes of dye-sensitized solar cells (DSSCs). By adjusting the shell thickness of CA@T NPs, the plasmonic property can be tuned to achieve maximum photovoltaic improvement. Furthermore, the DSSC cells fabricated with the CA@T NPs exhibit …

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Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov Jan 2015

Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov

Australian Institute for Innovative Materials - Papers

The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon …

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Contamination Mitigation Strategies For Scanning Transmission Electron Microscopy, David R. G Mitchell Jan 2015

Contamination Mitigation Strategies For Scanning Transmission Electron Microscopy, David R. G Mitchell

Australian Institute for Innovative Materials - Papers

Modern scanning transmission electron microscopy (STEM) enables imaging and microanalysis at very high magnification. In the case of aberration-corrected STEM, atomic resolution is readily achieved. However, the electron fluxes used may be up to three orders of magnitude greater than those typically employed in conventional STEM. Since specimen contamination often increases with electron flux, specimen cleanliness is a critical factor in obtaining meaningful data when carrying out high magnification STEM. A range of different specimen cleaning methods have been applied to a variety of specimen types. The contamination rate has been measured quantitatively to assess the effectiveness of cleaning. The …

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N-Doped Crumpled Graphene Derived From Vapor Phase Deposition Of Ppy On Graphene Aerogel As An Efficient Oxygen Reduction Reaction Electrocatalyst, Meng Wang, Jiazhao Wang, Yuyang Hou, Dongqi Shi, David Wexler, Simon D. Poynton, Robert C.T. Slade, Weimin Zhang, Hua-Kun Liu, Jun Chen Jan 2015

N-Doped Crumpled Graphene Derived From Vapor Phase Deposition Of Ppy On Graphene Aerogel As An Efficient Oxygen Reduction Reaction Electrocatalyst, Meng Wang, Jiazhao Wang, Yuyang Hou, Dongqi Shi, David Wexler, Simon D. Poynton, Robert C.T. Slade, Weimin Zhang, Hua-Kun Liu, Jun Chen

Australian Institute for Innovative Materials - Papers

Nitrogen-doped crumpled graphene (NCG) is successfully synthesized via vapor phase deposition of polypyrrole onto graphene aerogel followed by thermal treatment. The NCG was explored as an electrocatalyst for the oxygen reduction reaction, showing comparable electrocatalytic performance with the commercial Pt/C in alkaline membrane exchange fuel cells because of the well-regulated nitrogen doping and the robust micro-3D crumpled porous nanostructure.

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A Bi-Layer Tio2 Photoanode For Highly Durable, Flexible Dye-Sensitized Solar Cells, Jianjian Lin, Yong Peng, Alexander Pascoe, Fuzhi Huang, Yi-Bing Cheng, Yoon-Uk Heo, Andrew Nattestad, Wanchul Seung, Sung Kyun Kim, Hoon Joon Yoon, Sang Woo Kim, Yusuke Yamauchi, S X. Dou, Jung Ho Kim Jan 2015

A Bi-Layer Tio2 Photoanode For Highly Durable, Flexible Dye-Sensitized Solar Cells, Jianjian Lin, Yong Peng, Alexander Pascoe, Fuzhi Huang, Yi-Bing Cheng, Yoon-Uk Heo, Andrew Nattestad, Wanchul Seung, Sung Kyun Kim, Hoon Joon Yoon, Sang Woo Kim, Yusuke Yamauchi, S X. Dou, Jung Ho Kim

Australian Institute for Innovative Materials - Papers

Low-temperature processing of dye-sensitized solar cells (DSCs) [B. Oregan, M. Grätzel, Nature, 1991, 353, 737] is crucial to enable their commercialization with low-cost plastic substrates. Much of the previous work in this area has focused on mechanical compression of premade particles on plastic substrates; however, many reported that this technique did not yield sufficient interconnections for high charge carrier transport. Herein, we present bi-layer photoanodes that incorporate microstructured TiO2 sea-urchin-like assemblies, composed of high-aspect-ratio single crystalline nanoribbons, i.e., two-dimensional subunits, which were deposited onto a nanoparticle layer (commercial P25), with a 5.6% conversion efficiency realized. We demonstrate that …

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Large Entropy Change Accompanying Two Successive Magnetic Phase Transitions In Tbmn2si2 For Magnetic Refrigeration, Guoxing Li, Jianli Wang, Zhenxiang Cheng, Qing Yon Ren, Chunsheng Fang, S X. Dou Jan 2015

Large Entropy Change Accompanying Two Successive Magnetic Phase Transitions In Tbmn2si2 For Magnetic Refrigeration, Guoxing Li, Jianli Wang, Zhenxiang Cheng, Qing Yon Ren, Chunsheng Fang, S X. Dou

Australian Institute for Innovative Materials - Papers

Structural and magnetic properties in TbMn2Si2 are studied by variable temperature X-ray diffraction, magnetization, electrical resistivity, and heat capacity measurements. TbMn2Si2 undergoes two successive magnetic transitions at around Tc1 = 50 K and Tc2 = 64 K. Tc1 remains almost constant with increasing magnetic field, but Tc2 shifts significantly to higher temperature. Thus, there are two partially overlapping peaks in the temperature dependence of magnetic entropy change, i.e., −ΔSM (T). The different responses of Tc1 and Tc2 to external magnetic field, and the overlapping of −ΔSM …

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Chemically Converted Graphene: Scalable Chemistries To Enable Processing And Fabrication, Sanjeev Gambhir, Rouhollah Jalili, David L. Officer, Gordon G. Wallace Jan 2015

Chemically Converted Graphene: Scalable Chemistries To Enable Processing And Fabrication, Sanjeev Gambhir, Rouhollah Jalili, David L. Officer, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Graphene, a nanocarbon with exceptional physical and electronic properties, has the potential to be utilized in a myriad of applications and devices. However, this will only be achieved if scalable, processable forms of graphene are developed along with ways to fabricate these forms into material structures and devices. In this review, we provide a comprehensive overview of the chemistries suitable for the development of aqueous and organic solvent graphene dispersions and their use for the preparation of a variety of polymer composites, materials useful for the fabrication of graphene-containing structures and devices. Fabrication of the processable graphene dispersions or composites …

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Giant Enhancement In Critical Current Density, Up To A Hundredfold, In Superconducting Nafe0.97co0.03 As Single Crystals Under Hydrostatic Pressure, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, A-Li Wang, S X. Dou, X.H Chen Jan 2015

Giant Enhancement In Critical Current Density, Up To A Hundredfold, In Superconducting Nafe0.97co0.03 As Single Crystals Under Hydrostatic Pressure, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, A-Li Wang, S X. Dou, X.H Chen

Australian Institute for Innovative Materials - Papers

Tremendous efforts towards improvement in the critical current density "Jc" of iron based superconductors (FeSCs), especially at relatively low temperatures and magnetic fields, have been made so far through different methods, resulting in real progress. Jc at high temperatures in high fields still needs to be further improved, however, in order to meet the requirements of practical applications. Here, we demonstrate a simple approach to achieve this. Hydrostatic pressure can significantly enhance Jc in NaFe0.97Co0.03As single crystals by at least tenfold at low field and more than a hundredfold at high fields. …

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Strain-Induced Magnetic Phase Transition In Srcoo3−Δ Thin Films, S J. Callori, S Hu, Joel Bertinshaw, Zhilian Yue, S Danilkin, Xiaolin Wang, V Nagarajan, Frank Klose, Jan Seidel, Clemens Ulrich Jan 2015

Strain-Induced Magnetic Phase Transition In Srcoo3−Δ Thin Films, S J. Callori, S Hu, Joel Bertinshaw, Zhilian Yue, S Danilkin, Xiaolin Wang, V Nagarajan, Frank Klose, Jan Seidel, Clemens Ulrich

Australian Institute for Innovative Materials - Papers

It has been well established that both in bulk at ambient pressure and for films under modest strains, cubic SrCoO3−δ (δ<0.2) is a ferromagnetic metal. Recent theoretical work, however, indicates that a magnetic phase transition to an antiferromagnetic structure could occur under large strain accompanied by a metal-insulator transition. We have observed a strain-induced ferromagnetic-to-antiferromagnetic phase transition in SrCoO3−δ films grown on DyScO3 substrates, which provide a large tensile epitaxial strain, as compared to ferromagnetic films under lower tensile strain on SrTiO3 substrates. Magnetometry results demonstrate the existence of antiferromagnetic spin correlations and neutron diffraction experiments provide a direct evidence for a G-type antiferromagnetic structure with Neél temperatures between TN∼135±10K and ∼325±10K, depending on the oxygen content of the samples. Therefore, our data experimentally confirm the predicted strain-induced magnetic phase transition to an antiferromagnetic state for SrCoO3−δ thin films under large epitaxial strain.

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Effective Enhancement Of The Electrochemical Performance Of Layered Cathode Li1.5mn0.75ni0.25o2.5 Via A Novel Facile Molten Salt Method, Zhuo Zheng, Wei-Bo Hua, S Liao, Yan Jun Zhong, En-Hui Wang, Bin-Bin Xu, Hua-Kun Liu, Ben-He Zhong Jan 2015

Effective Enhancement Of The Electrochemical Performance Of Layered Cathode Li1.5mn0.75ni0.25o2.5 Via A Novel Facile Molten Salt Method, Zhuo Zheng, Wei-Bo Hua, S Liao, Yan Jun Zhong, En-Hui Wang, Bin-Bin Xu, Hua-Kun Liu, Ben-He Zhong

Australian Institute for Innovative Materials - Papers

A series of nanocrystalline lithium-rich cathode materials Li1.5Mn0.75Ni0.25O2.5 have been prepared by a novel synthetic process, which combines the co-precipitation method and a modified molten salt method. By using a moderate excess of 0.5LiNO3-0.5LiOH eutectic salts as molten media and reactants, the usage of deionized water or alcohol in the subsequent wash process is successfully reduced, compared with the traditional molten salt method. The materials with different excess Li salt content, Li/M (M = Ni + Mn) = 1.55, 1.65, 1.75, 1.85, 1.95, 2.05, molar ratio, show distinct differences in their …

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Ferroelectric And Magnetic Properties Of Aurivillius Bim+1ti3fem−3o3m+3 Thin Films, Tingting Jia, Hideo Kimura, Zhenxiang Cheng, Hongyang Zhao Jan 2015

Ferroelectric And Magnetic Properties Of Aurivillius Bim+1ti3fem−3o3m+3 Thin Films, Tingting Jia, Hideo Kimura, Zhenxiang Cheng, Hongyang Zhao

Australian Institute for Innovative Materials - Papers

Aurivillius Bim+1Ti3Fem−3O3m+3 (m = 4, 5, 6) thin films have been deposited by a pulsed laser deposition system. The x-ray diffraction patterns indicate the formation of orthorhombic phase. The remanent polarization (2Pr) of Bim+1Ti3Fem−3O3m+3 thin films is decreased with the m-number. Positive-up-negative-down measurements indicate the presence of ferroelectric (FE) polarization in as-obtained thin films. Piezoresponse force microscopy investigations confirm the existence of FE domains and the switchable polarization. Weak magnetic moment is detected in the Aurivillius films at room temperature. The present work …

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Superior Critical Current Density Obtained In Mg11b2 Low Activation Superconductor By Using Reactive Amorphous 11b And Optimizing Sintering Temperature, Fang Cheng, Yongchang Liu, Zongqing Ma, Huijun Li, Md Shahriar Hossain Jan 2015

Superior Critical Current Density Obtained In Mg11b2 Low Activation Superconductor By Using Reactive Amorphous 11b And Optimizing Sintering Temperature, Fang Cheng, Yongchang Liu, Zongqing Ma, Huijun Li, Md Shahriar Hossain

Australian Institute for Innovative Materials - Papers

The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by solid-state reaction and sintered at different temperature in present work. By analyzing the sintering process, it was found that 11B original powder is more reactive and can react with Mg severely even at low temperature before Mg melting, which leads to the formation of refined Mg11B2 grains. Consequently, the critical current density of Mg11B2 sample prepared in this work is higher than that of natural MgB2. Furthermore, it was found that proper Cu addition …

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Probe Current Determination In Analytical Tem/Stem And Its Application To The Characterization Of Large Area Eds Detectors, David R. G Mitchell, Mitchell John Bromley Nancarrow Jan 2015

Probe Current Determination In Analytical Tem/Stem And Its Application To The Characterization Of Large Area Eds Detectors, David R. G Mitchell, Mitchell John Bromley Nancarrow

Australian Institute for Innovative Materials - Papers

A simple procedure, which enables accurate measurement of transmission electron microscopy (TEM)/STEM probe currents using an energy loss spectrometer drift tube is described. The currents obtained are compared with those measured on the fluorescent screen to enable the losses due to secondary and backscattered electrons to be determined. The current values obtained from the drift tube allow the correction of fluorescent screen current densities to yield true current. They also enable CCD conversion efficiencies to be obtained, which in turn allows images to be calibrated in terms of electron fluence. Using probes of known current in conjunction with a NiO …

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Robust Scalable Synthesis Of Surfactant-Free Thermoelectric Metal Chalcogenide Nanostructures, Chao Han, Zhen Li, Gao Qing (Max) Lu, S X. Dou Jan 2015

Robust Scalable Synthesis Of Surfactant-Free Thermoelectric Metal Chalcogenide Nanostructures, Chao Han, Zhen Li, Gao Qing (Max) Lu, S X. Dou

Australian Institute for Innovative Materials - Papers

A robust low-cost ambient aqueous method for the scalable synthesis of surfactant-free nanostructured metal chalcogenides (MaXb, M=Cu, Ag, Sn, Pb, and Bi; X=S, Se, and Te; a=1 or 2; and b=1 or 3) is developed in this work. The effects of reaction parameters, such as precursor concentration, ratio of precursors, and amount of reducing agent, on the composition, size, and shape of the resultant nanostructures have been comprehensively investigated. This environmentally friendly approach is capable of producing metal chalcogenide nanostructures in a one-pot reaction on a large scale, which were investigated for their thermoelectric properties towards conversion of waste heat …

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The Codes Of Matter And Their Applications, Xiaolin Wang Jan 2015

The Codes Of Matter And Their Applications, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

The elements in the periodic table are the building blocks used to form substances with different compositions. Nevertheless, it is the properties of substances that are decisive for their existence and practical applications. Searching for new class of materials with exotic properties has always been challenging because of the complexity of both the theoretical and the experimental approaches developed so far. Here, we propose that the three ubiquitous and paramount attributes of all existing matter charge (Q), spin (S) or rotational motion, and linear motion (K) can be used to account for the formation of different types of matter/materials and …

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An Intermediate Band Dye-Sensitised Solar Cell Using Triplet-Triplet Annihilation, Catherine Simpson, Tracey M. Clarke, Rowan W. Macqueen, Yuen Yap Cheng, Adam J. Trevitt, Attila J. Mozer, Pawel W. Wagner, Timothy W. Schmidt, Andrew Nattestad Jan 2015

An Intermediate Band Dye-Sensitised Solar Cell Using Triplet-Triplet Annihilation, Catherine Simpson, Tracey M. Clarke, Rowan W. Macqueen, Yuen Yap Cheng, Adam J. Trevitt, Attila J. Mozer, Pawel W. Wagner, Timothy W. Schmidt, Andrew Nattestad

Australian Institute for Innovative Materials - Papers

A new mechanism of charge photogeneration is demonstrated for the first time, based on organic molecular structures. This intermediate band approach, integrated into a dye-sensitised solar cell configuration is shown to generate charges upon illumination with low energy photons. Specifically 610 nm photoexcitation of Pt porphyrins, through a series of energy transfer steps and triplet-triplet annihilation, excites a higher energy absorption onset molecule, which is then capable of charge injection into TiO2. Transient absorption measurements reveal further detail of the processes involved.

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A Decaheme Cytochrome As A Molecular Electron Conduit In Dye-Sensitized Photoanodes, Ee Taek Hwang, Khizar Sheikh, Katherine L. Orchard, Daisuke Hojo, Valentin Radu, Chong-Yong Lee, Emma Ainsworth, Colin Lockwood, Manuela A. Gross, Tadafumi Adschiri, Erwin Reisner, Julea N. Butt, Lars J. C Jeuken Jan 2015

A Decaheme Cytochrome As A Molecular Electron Conduit In Dye-Sensitized Photoanodes, Ee Taek Hwang, Khizar Sheikh, Katherine L. Orchard, Daisuke Hojo, Valentin Radu, Chong-Yong Lee, Emma Ainsworth, Colin Lockwood, Manuela A. Gross, Tadafumi Adschiri, Erwin Reisner, Julea N. Butt, Lars J. C Jeuken

Australian Institute for Innovative Materials - Papers

In nature, charge recombination in light-harvesting reaction centers is minimized by efficient charge separation. Here, it is aimed to mimic this by coupling dye-sensitized TiO2 nanocrystals to a decaheme protein, MtrC from Shewanella oneidensis MR-1, where the 10 hemes of MtrC form a ≈7-nm-long molecular wire between the TiO2 and the underlying electrode. The system is assembled by forming a densely packed MtrC film on an ultra-flat gold electrode, followed by the adsorption of approximately 7 nm TiO2 nanocrystals that are modified with a phosphonated bipyridine Ru(II) dye (RuP). The step-by-step construction of the MtrC/TiO2 system is monitored with (photo)electrochemistry, …

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Multiple Fermi Pockets Revealed By Shubnikov-De Haas Oscillations In Wte2, Feixiang Xiang, Menno Veldhorst, S X. Dou, Xiaolin Wang Jan 2015

Multiple Fermi Pockets Revealed By Shubnikov-De Haas Oscillations In Wte2, Feixiang Xiang, Menno Veldhorst, S X. Dou, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

The recently discovered non-saturating and parabolic magnetoresistance and the pressure-induced superconductivity at low temperature in WTe2 imply its rich electronic structure and possible practical applications. Here we use magnetotransport measurements to investigate the electronic structure of WTe2 single crystals. A non-saturating and parabolic magnetoresistance is observed from low temperature to high temperature up to 200 K with magnetic fields up to 8 T. Shubnikov-de Haas (SdH) oscillations with beating patterns are observed, the fast Fourier transform of which reveals three oscillation frequencies, corresponding to three pairs of Fermi pockets with comparable effective masses, m∗∼0.31 me. By fitting the Hall resistivity, …

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Mechanism Of Periodic Height Variations Along Self-Aligned Vls-Grown Planar Nanostructures, Julian Steele, Josip Horvat, Roger A. Lewis, M Henini, D. Fan, Yu. I. Mazur, V G. Dorogan, P C. Grant, S.-Q Yu, G J. Salamo Jan 2015

Mechanism Of Periodic Height Variations Along Self-Aligned Vls-Grown Planar Nanostructures, Julian Steele, Josip Horvat, Roger A. Lewis, M Henini, D. Fan, Yu. I. Mazur, V G. Dorogan, P C. Grant, S.-Q Yu, G J. Salamo

Australian Institute for Innovative Materials - Papers

In this study we report in-plane nanotracks produced by molecular-beam-epitaxy (MBE) exhibiting lateral self-assembly and unusual periodic and out-of-phase height variations across their growth axes. The nanotracks are synthesized using bismuth segregation on the GaAsBi epitaxial surface, which results in metallic liquid droplets capable of catalyzing GaAsBi nanotrack growth via the vapor-liquid-solid (VLS) mechanism. A detailed examination of the nanotrack morphologies is carried out employing a combination of scanning electron and atomic force microscopy and, based on the findings, a geometric model of nanotrack growth during MBE is developed. Our results indicate diffusion and shadowing effects play significant roles in …

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