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Full-Text Articles in Engineering

Investigation Of Phase Composition And Nanoscale Microstructure Of High-Energy Ball-Milled Mgcu Sample, Zongqing Ma, Yongchang Liu, Liming Yu, Qi Cai Jan 2012

Investigation Of Phase Composition And Nanoscale Microstructure Of High-Energy Ball-Milled Mgcu Sample, Zongqing Ma, Yongchang Liu, Liming Yu, Qi Cai

Australian Institute for Innovative Materials - Papers

The ball milling technique has been successfully applied to the synthesis of various materials such as equilibrium intermetallic phases, amorphous compounds, nanocrystalline materials, or metastable crystalline phases. However, how the phase composition and nanoscale microstructure evolute during ball milling in various materials is still controversial due to the complex mechanism of ball milling, especially in the field of solid-state amorphization caused by ball milling. In the present work, the phase evolution during the high-energy ball milling process of the Mg and Cu (atomic ratio is 1:1) mixed powder was investigated. It was found that Mg firstly reacts with Cu, forming …


Enhanced X-Ray Imaging For A Thin Film Cochlear Implant With Metal Artefacts Using Phase Retrieval Tomography, B D. Arhatari, Alexander R. Harris, Antonio G. Paolini, Andrew G. Peele Jan 2012

Enhanced X-Ray Imaging For A Thin Film Cochlear Implant With Metal Artefacts Using Phase Retrieval Tomography, B D. Arhatari, Alexander R. Harris, Antonio G. Paolini, Andrew G. Peele

Australian Institute for Innovative Materials - Papers

Phase retrieval tomography has been successfully used to enhance imaging in systems that exhibit poor absorption contrast. However, when highly absorbing regions are present in a sample, so-called metal artefacts can appear in the tomographic reconstruction. We demonstrate that straightforward approaches for metal artefact reconstruction, developed in absorption contrast tomography, can be applied when using phase retrieval. Using a prototype thin film cochlear implant that has high and low absorption components made from iridium (or platinum) and plastic, respectively, we show that segmentation of the various components is possible and hence measurement of the electrode geometry and relative location to …


One-Pot Synthesis Of Colloidal Silicon Quantum Dots And Surface Functionalization Via Thiol-Ene Click Chemistry, Xiaoyu Cheng, Richard Gondosiswanto, Simone Ciampi, Peter J. Reece, J Justin Gooding Jan 2012

One-Pot Synthesis Of Colloidal Silicon Quantum Dots And Surface Functionalization Via Thiol-Ene Click Chemistry, Xiaoyu Cheng, Richard Gondosiswanto, Simone Ciampi, Peter J. Reece, J Justin Gooding

Australian Institute for Innovative Materials - Papers

A solution method for preparing surface functionalized colloidal silicon quantum dots (SiQDs) is presented. SiQDs prepared by this method are reasonably monodispersed and can be further functionalized via thiol-ene click reactions to introduce specific functionalities (i.e. -NH2, -COOH, -SO 3 -, alkane, alkene).


Structure Determination Of An Amorphous Compound Alb4h11, Xuenian Chen, Yongsheng Zhang, Yongli Wang, Wei Zhou, Douglas A. Knight, Teshome B. Yisgedu, Zhenguo Huang, Hima Kumar Lingam, Beau Billet, Terrence J. Udovic, Gilbert M. Brown, Sheldon G. Shore, Christopher Wolverton, Ji-Cheng Zhao Jan 2012

Structure Determination Of An Amorphous Compound Alb4h11, Xuenian Chen, Yongsheng Zhang, Yongli Wang, Wei Zhou, Douglas A. Knight, Teshome B. Yisgedu, Zhenguo Huang, Hima Kumar Lingam, Beau Billet, Terrence J. Udovic, Gilbert M. Brown, Sheldon G. Shore, Christopher Wolverton, Ji-Cheng Zhao

Australian Institute for Innovative Materials - Papers

No abstract provided.


A Novel Route To Copper(Ii) Detection Using 'Click' Chemistry-Induced Aggregation Of Gold Nanoparticles, Carol Hua, William H. Zhang, Swahnnya De Almeida, Simone Ciampi, Danmar Gloria, Guozhen Liu, Jason Brian Harper, J Justin Gooding Jan 2012

A Novel Route To Copper(Ii) Detection Using 'Click' Chemistry-Induced Aggregation Of Gold Nanoparticles, Carol Hua, William H. Zhang, Swahnnya De Almeida, Simone Ciampi, Danmar Gloria, Guozhen Liu, Jason Brian Harper, J Justin Gooding

Australian Institute for Innovative Materials - Papers

A simple colorimetric method for the detection of copper ions in water is described. This method is based on the 'click' copper(i)-catalyzed azide-alkyne cycloaddition reaction and its use in promoting the aggregation of azide-tagged gold nanoparticles by a dialkyne cross-linker is described. Nanoparticle cross-linking, evidenced as a colour change, is used for the detection of copper ions. The lowest detected concentration by the naked eye was 1.8 μM, with the response linear with log(concentration) between 1.8-200 μM. The selectivity relative to other potentially interfering ions was evaluated.


The Synthesis Of Lamellar Nano Mgb2 Grains With Nanoimpurities, Flux Pinning Centers And Their Significantly Improved Critical Current Density, Zongqing Ma, Yongchang Liu, Qi Cai Jan 2012

The Synthesis Of Lamellar Nano Mgb2 Grains With Nanoimpurities, Flux Pinning Centers And Their Significantly Improved Critical Current Density, Zongqing Ma, Yongchang Liu, Qi Cai

Australian Institute for Innovative Materials - Papers

MgB2 superconductors with unique microstructures were rapidly fabricated at low temperatures, and exhibited significantly improved critical current density (Jc). According to the microstructure observations, the prepared samples consisted of lamellar nano MgB2 grains with many embedded nanoimpurities (about 10 nm). The formation of these lamellar nano MgB2 grains is associated with the presence of a local Mg-Cu liquid at sintering temperatures as low as 575°C. The ball milling treatment of the original powders also plays a positive role in the growth of lamellar grains. Based on an analysis of the relationship between resistivity and temperature, the lamellar nano MgB2 grains …


Kfe2se2 Is The Parent Compound Of K-Doped Iron Selenide Superconductors, Weijie Li, Hao Ding, Zhi Li, Peng Deng, Kai Chang, Ke He, Shuaihua Ji, Lili Wang, Xu-Cun Ma, Jiang-Ping Hu, Xi Chen, Qi-Kun Xue Jan 2012

Kfe2se2 Is The Parent Compound Of K-Doped Iron Selenide Superconductors, Weijie Li, Hao Ding, Zhi Li, Peng Deng, Kai Chang, Ke He, Shuaihua Ji, Lili Wang, Xu-Cun Ma, Jiang-Ping Hu, Xi Chen, Qi-Kun Xue

Australian Institute for Innovative Materials - Papers

We elucidate the existing controversies in the newly discovered K-doped iron selenide (KxFe2ySe2z) superconductors. The stoichiometric KFe2Se2 with ffiffiffi 2 p ffiffiffi 2 p charge ordering was identified as the parent compound of KxFe2ySe2z superconductor using scanning tunneling microscopy and spectroscopy. The superconductivity is induced in KFe2Se2 by either Se vacancies or interacting with the antiferromagnetic K2Fe4Se5 compound. In total, four phases were found to exist in KxFe2ySe2z: parent compound KFe2Se2, superconducting KFe2Se2 with ffiffiffi 2 p ffiffiffi 5 p charge ordering, superconducting KFe2Se2z with Se vacancies, and insulating K2Fe4Se5 with ffiffiffi 5 p ffiffiffi 5 p Fe vacancy order. …


Gating The Charge State Of Single Fe Dopants In The Topological Insulator Bi 2 Se 3 With A Scanning Tunneling Microscope, Canli Song, Yeping Jiang, Yi-Lin Wang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue Jan 2012

Gating The Charge State Of Single Fe Dopants In The Topological Insulator Bi 2 Se 3 With A Scanning Tunneling Microscope, Canli Song, Yeping Jiang, Yi-Lin Wang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue

Australian Institute for Innovative Materials - Papers

Low-temperature scanning tunneling microscope (STM) is exploited to study directly the atomic and electronic structures of single Fe dopants in topological insulator Bi2Se3 thin films. Fe atoms predominantly and isovalently substitute for two distinct Bi sites at the subsurface with charge neutrality. In the vicinity of Fe substitutions, circular depressions in STM topography and sharp rings in spatially resolved conductance map, whose diameters apparently depend on the tunneling conditions, are observed. We show that the phenomena correlate well with the switching between Fe3+ and Fe2+ charge states due to the gate effect of the tunneling tip, as further evidenced by …


A Battery Composed Of A Polypyrrole Cathode And A Magnesium Alloy Anode-Toward A Bioelectric Battery, Yong Kong, Caiyun Wang, Yang Yang, Chee O. Too, Gordon G. Wallace Jan 2012

A Battery Composed Of A Polypyrrole Cathode And A Magnesium Alloy Anode-Toward A Bioelectric Battery, Yong Kong, Caiyun Wang, Yang Yang, Chee O. Too, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

A bioelectric battery can be implanted into the human body and relies on oxygen in the internal body fluid to produce electrical energy. In this work, a battery that uses polypyrrole doped with a biological polyelectrolyte (dextran sulfate, an anti-coagulant) as the cathode and bioresorbable Mg alloy (AZ61) as the anode was developed. This battery exhibited a discharge capacity of 565 mA h g-1 in phosphate buffered saline (PBS, pH = 7.4), a commonly used electrolyte in biological research; offering a specific energy density of similar to 790W h kg-1. The electrochemical properties of the cathode, anode …


Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou Jan 2012

Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou

Australian Institute for Innovative Materials - Papers

Magnetic properties and the magnetocaloric effect (MCE) have been investigated in La0.7Ca0.3MnO3 single crystal with applied field along both the ab-plane and the c-direction. Due to the magnetocrystalline anisotropy, the crystal exhibits anisotropy in the MCE. Upon application of a 5 T field, the magnetic entropy changes (SM), reaching values of 7.668 J/(kg K) and 6.412 J/(kg K) for both the ab-plane and the c-direction, respectively. A magnetic entropy change of 3.3 J/(kg K) was achieved for a magnetic field change of 1.5 T at the Curie temperature, TC = 245 K. Due to the absence of grains in the …


High Field (14 T) Magneto Transport Of Sm/Prfeaso, R S. Meena, Shiva Kumar Singh, Anand Pal, Anuj Kumar, R Jha, K V.R Rao, Yi Du, Xiaolin Wang, V P. Awana Jan 2012

High Field (14 T) Magneto Transport Of Sm/Prfeaso, R S. Meena, Shiva Kumar Singh, Anand Pal, Anuj Kumar, R Jha, K V.R Rao, Yi Du, Xiaolin Wang, V P. Awana

Australian Institute for Innovative Materials - Papers

We report high field magneto transport of Sm/PrFeAsO. Below spin density wave transition (TSDW), the magneto-resistance (MR) of Sm/PrFeAsO is positive and increasing with decreasing temperature. The MR of SmFeAsO is found to be 16%, whereas it is 21.5% in the case of PrFeAsO, at 2.5K under applied magnetic field of 14 Tesla (T). In the case of SmFeAsO, the variation of isothermal MR with field below 20 K is nonlinear at lower magnetic fields (3.5 T). On the other hand, PrFeAsO shows almost linear MR at all temperatures below 20 K. The anomalous behavior of MR being …


Ferroelectric And Ferromagnetic Nanofibers: Synthesis, Properties And Applications, A Jalalian, A M. Grishin, S X. Dou Jan 2012

Ferroelectric And Ferromagnetic Nanofibers: Synthesis, Properties And Applications, A Jalalian, A M. Grishin, S X. Dou

Australian Institute for Innovative Materials - Papers

As first time, ferroelectric (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCTZ), biocompatible (Na0.5K0.5)NbO3 (NKN), and ferromagnetic Y3Fe5O12 (YIG) nanofibers were synthesized by sol-gel assisted electrospining technique. Non-woven, bead-free 100 μm long fiber mat was formed from close-packed nanocrystals after calcination in air at 800°C (BCTZ and NKN) and 1100°C (YIG). BCTZ fibers are 200 nm in width whereas NKN and YIG fibers have smaller 50-100 nm diameter. X-ray diffraction and Raman spectroscopy show that BCTZ and NKN crystallized in tetragonal and rhombohedral polar phases in the vicinity of morphotropic phase boundary. …


Vapor Phase Polymerization Of Edot From Submicrometer Scale Oxidant Patterned By Dip-Pen Nanolithography, Cathal D. O'Connell, Michael J. Higgins, Hiroshi Nakashima, Simon E. Moulton, Gordon G. Wallace Jan 2012

Vapor Phase Polymerization Of Edot From Submicrometer Scale Oxidant Patterned By Dip-Pen Nanolithography, Cathal D. O'Connell, Michael J. Higgins, Hiroshi Nakashima, Simon E. Moulton, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Some of the most exciting recent advances in conducting polymer synthesis have centered around the method of vapor phase polymerization (VPP) of thin films. However, it is not known whether the VPP process can proceed using significantly reduced volumes of oxidant and therefore be implemented as part of nanolithography approach. Here, we present a strategy for submicrometer scale patterning of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) via in situ VPP. Attolitre (10-18 L) volumes of oxidant "ink" are controllably deposited using dip-pen nanolithography (DPN). DPN patterning of the oxidant ink is facilitated by the incorporation of an amphiphilic block copolymer …


The Role Of Unbound Oligomers In The Nucleation And Growth Of Electrodeposited Polypyrrole And Method For Preparing High Strength, High Conductivity Films, Wen Zheng, Joselito M. Razal, Geoffrey M. Spinks, Van-Tan Truong, Philip G. Whitten, Gordon G. Wallace Jan 2012

The Role Of Unbound Oligomers In The Nucleation And Growth Of Electrodeposited Polypyrrole And Method For Preparing High Strength, High Conductivity Films, Wen Zheng, Joselito M. Razal, Geoffrey M. Spinks, Van-Tan Truong, Philip G. Whitten, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Polypyrrole is a material with immensely useful properties suitable for a wide range of electrochemical applications, but its development has been hindered by cumbersome manufacturing processes. Here we show that a simple modification to the standard electrochemical polymerization method produces polypyrrole films of equivalently high conductivity and superior mechanical properties in one-tenth of the polymerization time. Preparing the film as a series of electrodeposited layers with thorough solvent washing between layering was found to produce excellent quality films even when layer deposition was accelerated by high current. The washing step between the sequentially polymerized layers altered the deposition mechanism, eliminating …


Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou Jan 2012

Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou

Australian Institute for Innovative Materials - Papers

Polycrystalline (PC) and single crystalline (SC) samples of La0.7Ca0.3CoO3 (LCCO) with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We conducted isothermal magnetization measurements of the PC and SC samples at temperatures from 2.8 K to 140 K, and evaluated the magnetic entropy change (−ΔSM) under zero field cooling (ZFC) and field cooling (FC) to 2.8 K. An interesting result has been obtained, where the −ΔSM–T curves in the low temperature range show totally different features between the ZFC and FC cooling procedures. The −ΔS …


Why Do Girls Sustain More Anterior Cruciate Ligament Injuries Than Boys? A Review Of The Changes In Oestrogen And Musculoskeletal Structure And Function During Puberty, Catherine Y. Wild, Julie R. Steele, Bridget J. Munro Jan 2012

Why Do Girls Sustain More Anterior Cruciate Ligament Injuries Than Boys? A Review Of The Changes In Oestrogen And Musculoskeletal Structure And Function During Puberty, Catherine Y. Wild, Julie R. Steele, Bridget J. Munro

Australian Institute for Innovative Materials - Papers

Sport is the leading cause of injury among adolescents and girls incur more non-contact anterior cruciate ligament (ACL) ruptures than boys, with this gender disparity in injury incidence apparent from the onset of puberty. Although the mechanisms for this gender disparity in ACL injuries are relatively unknown, hormonal, anatomical and biomechanical factors have been implicated. Puberty is associated with rapid skeletal growth and hormonal influx, both of which are thought to contribute to alterations in ACL metabolic and mechanical properties, as well as changes in lower limb strength and flexibility, ultimately influencing landing technique. Therefore, the aim of this review …


K0.25mn2o4 Nanofiber Microclusters As High Power Cathode Materials For Rechargeable Lithium Batteries, Chaofeng Zhang, Chuanqi Feng, Peng Zhang, Zaiping Guo, Zhixin Chen, Sean Li, Hua-Kun Liu Jan 2012

K0.25mn2o4 Nanofiber Microclusters As High Power Cathode Materials For Rechargeable Lithium Batteries, Chaofeng Zhang, Chuanqi Feng, Peng Zhang, Zaiping Guo, Zhixin Chen, Sean Li, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

K0.25Mn2O4 microclusters assembled from single-crystalline nanofibers were synthesized via a hydrothermal process at different temperatures. The possibility of using these materials as cathode material for lithium ion batteries was studied for the first time. The charge/discharge results showed that the K0.25Mn2O4 nanofiber microclusters synthesized at 120 degrees C exhibit excellent lithium storage properties, with a high reversible capability (360 mA h g-1 at current density of 100 mA g-1) and stable lithium-ion insertion/de-insertion reversibility. The charge/discharge mechanism in lithium ion batteries was studied and proposed for the …


Microscopic Role Of Carbon On Mgb2 Wire For Critical Current Density Comparable To Nbti, Jung Ho Kim, Sangjun Oh, Yoon-Uk Heo, Satoshi Hata, Hiroaki Kumakura, Akiyoshi Matsumoto, Masatoshi Mitsuhara, Seyong Choi, Yusuke Shimada, Minoru Maeda, Judith Macmanus-Driscoll, S X. Dou Jan 2012

Microscopic Role Of Carbon On Mgb2 Wire For Critical Current Density Comparable To Nbti, Jung Ho Kim, Sangjun Oh, Yoon-Uk Heo, Satoshi Hata, Hiroaki Kumakura, Akiyoshi Matsumoto, Masatoshi Mitsuhara, Seyong Choi, Yusuke Shimada, Minoru Maeda, Judith Macmanus-Driscoll, S X. Dou

Australian Institute for Innovative Materials - Papers

Increasing dissipation-free supercurrent has been the primary issue for practical application of superconducting wires. For magnesium diboride, MgB2, carbon is known to be the most effective dopant to enhance high-field properties. However, the critical role of carbon remains elusive, and also low-field critical current density has not been improved. Here, we have undertaken malic acid doping of MgB2 and find that the microscopic origin for the enhancement of high-field properties is due to boron vacancies and associated stacking faults, as observed by high-resolution transmission electron microscopy and electron energy loss spectroscopy. The carbon from the malic acid almost uniformly encapsulates …


Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler Jan 2012

Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler

Australian Institute for Innovative Materials - Papers

Free-standingsingle-walledcarbonnanotube/SnO2 (SWCNT/SnO2) anodepaper was prepared by vacuum filtration of SWCNT/SnO2 hybrid material which was synthesized by the polyol method. From field emission scanning electron microscopy and transmission electron microscopy, the CNTs form a three-dimensional nanoporous network, in which ultra-fine SnO2 nanoparticles, which had crystallite sizes of less than 5 nm, were distributed, predominately as groups of nanoparticles on the surfaces of singlewalled CNT bundles. Electrochemical measurements demonstrated that the anodepaper with 34 wt.% SnO2 had excellent cyclic retention, with the high specific capacity of 454 mAh g−1 beyond 100 cycles at a current …


Isomorphism In Two (E)-1-(4-Halophenyl)-N-[1-(4-Methylphenyl)-1h-Imidazol-4-Yl]Methanimines (Halide = Cl, Br), Hanna Skrzypiec, Radoslaw Mazurek, Pawel Wagner, Maciej Kubicki Jan 2012

Isomorphism In Two (E)-1-(4-Halophenyl)-N-[1-(4-Methylphenyl)-1h-Imidazol-4-Yl]Methanimines (Halide = Cl, Br), Hanna Skrzypiec, Radoslaw Mazurek, Pawel Wagner, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

The crystal structures of two imidazole-4-imines, (E)-1-(4-chlorophenyl)-N-[1-(4-methylphenyl)-1H-imidazol-4-yl]methanimine (1, C17H14ClN3), and (E)-1-(4-bromophenyl)-N-[1-(4-methylphenyl)-1H-imidazol-4-yl]methanimine, (2, C17H14BrN3), are isomorphous, the isostructurality index is 99.4 %. Both compounds crystallize in the triclinic space group P-1 with unit cell parameters at 100(1) K as follows: for (1), a = 7.9767(5) Å, b = 10.9517(7) Å, c = 16.6753(12) Å, α = 80.522(6)°, β = 87.046(6)°, γ = 89.207(5)°, and for (2), a = 8.0720(7) Å, b = 10.9334(10) Å, c = 16.8433(13) Å, α = 81.161(7)°, β = 86.605(7)°, γ = 89.505(7)°. The structures contain two symmetry—independent but conformationally similar molecules in the asymmetric unit (Z’ …


Synthesis And Electrochemical Characterization Of Lifepo4/C-Polypyrrole Composite Prepared By A Simple Chemical Vapor Deposition Method, Qiang Gong, Yu-Shi He, Yang Yang, Xiao Zhen Liao, Zi-Feng Ma Jan 2012

Synthesis And Electrochemical Characterization Of Lifepo4/C-Polypyrrole Composite Prepared By A Simple Chemical Vapor Deposition Method, Qiang Gong, Yu-Shi He, Yang Yang, Xiao Zhen Liao, Zi-Feng Ma

Australian Institute for Innovative Materials - Papers

A LiFePO4/C-polypyrrole (LiFePO4/C-PPy) composite as a high-performance cathode material is successfully prepared through a simple chemical vapor deposition (CVD) method. According to the transmission electron microscope (TEM) analysis, the surface of the LiFePO4/C is surrounded with PPy in the LiFePO4/C-PPy composite. The as-prepared LiFePO4/C-PPy material shows outstanding rate capability at 20°C and good cycle performance at 55°C in comparison with those of the bare LiFePO4/C material against Li anode. After 700 cycles, the discharge capacity of LiFePO4/C-PPy could still remain 110 mA h g−1 with …


Quasi-One-Dimensional Intermittent Flux Behavior In Superconducting Films, A J. Qviller, V V. Yurchenko, Y M. Galperin, J I. Vestgarden, P B. Mozhaeva, J B. Hansen, T H. Johansen Jan 2012

Quasi-One-Dimensional Intermittent Flux Behavior In Superconducting Films, A J. Qviller, V V. Yurchenko, Y M. Galperin, J I. Vestgarden, P B. Mozhaeva, J B. Hansen, T H. Johansen

Australian Institute for Innovative Materials - Papers

Intermittent filamentary dynamics of the vortex matter in superconductors is found in films of YBa2Cu3O7-δ deposited on tilted substrates. Deposition of this material on such substrates creates parallel channels of easy flux penetration when a magnetic field is applied perpendicular to the film. As the applied field is gradually increased, magneto-optical imaging reveals that flux penetrates via numerous quasi-one-dimensional jumps. The distribution of flux avalanche sizes follows a power law, and data collapse is obtained by finite-size scaling, with the depth of the flux front used as crossover length. The intermittent behavior shows no threshold …


Methane Activation On Fe4 Cluster: A Density Functional Theory Study, Qiao Sun, Zhen Li, Meng Wang, Aijun Du, Sean C. Smith Jan 2012

Methane Activation On Fe4 Cluster: A Density Functional Theory Study, Qiao Sun, Zhen Li, Meng Wang, Aijun Du, Sean C. Smith

Australian Institute for Innovative Materials - Papers

We report a comprehensive theoretical study on reaction of methane by Fe4 cluster. This Letter gains insight into the mechanism of the reaction and indicate the Fe4 cluster has strong catalytic effect on the activation reaction of methane. In detail, the results show the cleavage of the first C-H bond is both an energetically and kinetically favourable process and the breaking of the second C-H is the rate-determining step. Moreover, our Letter demonstrates that the different cluster size of iron can not only determine the catalytic activity of methane but also control the product selectivity.


Boron-Nitrogen-Hydrogen (Bnh) Compounds: Recent Developments In Hydrogen Storage, Applications In Hydrogenation And Catalysis, And New Syntheses, Zhenguo Huang, Tom Autrey Jan 2012

Boron-Nitrogen-Hydrogen (Bnh) Compounds: Recent Developments In Hydrogen Storage, Applications In Hydrogenation And Catalysis, And New Syntheses, Zhenguo Huang, Tom Autrey

Australian Institute for Innovative Materials - Papers

The strong efforts devoted to the exploration of BNH compounds for hydrogen storage have led to impressive advances in the field of boron chemistry. This review summarizes progress in this field from three aspects. It starts with the most recent developments in using BNH compounds for hydrogen storage, covering NH3BH3, B3H8- containing compounds, and CBN compounds. The following section then highlights interesting applications of BNH compounds in hydrogenation and catalysis. The last part is focused on breakthroughs in the syntheses and discovery of new BNH organic analogues. The role of N-Hδ+ …


Efficiency Of A Compact Elliptical Planar Ultra-Wideband Antenna Based On Conductive Polymers, Thomas Kaufmann, Akhilesh Verma, Van-Tan Truong, Bo Weng, Roderick Shepherd, Christopher Fumeaux Jan 2012

Efficiency Of A Compact Elliptical Planar Ultra-Wideband Antenna Based On Conductive Polymers, Thomas Kaufmann, Akhilesh Verma, Van-Tan Truong, Bo Weng, Roderick Shepherd, Christopher Fumeaux

Australian Institute for Innovative Materials - Papers

A planar antenna for ultra-wideband (UWB) applications covering the 3.1–10.6 GHz range has been designed as a test bed for efficiency measurements of antennas manufactured using polymer conductors. Two types of conductive polymers, PEDOT and PPy (polypyrrole), with very different thicknesses and conductivities have been selected as conductors for the radiating elements. A comparison between measured radiation patterns of the conductive polymers and a copper reference antenna allows to estimate the conductor losses of the two types of conductive polymers. For a 158 μm thick PPy polymer, an efficiency of almost 80% can be observed over the whole UWB spectrum. …


Improved Photovoltaic Performance Of Dye-Sensitized Solar Cells With Modified Self-Assembling Highly Ordered Mesoporous Tio2 Photoanodes, Ziqi Sun, Jung Ho Kim, Yue Zhao, Fargol Bijarbooneh, Victor Malgras, S X. Dou Jan 2012

Improved Photovoltaic Performance Of Dye-Sensitized Solar Cells With Modified Self-Assembling Highly Ordered Mesoporous Tio2 Photoanodes, Ziqi Sun, Jung Ho Kim, Yue Zhao, Fargol Bijarbooneh, Victor Malgras, S X. Dou

Australian Institute for Innovative Materials - Papers

Strategies for improving the photovoltaic performance of dye-sensitized solar cells (DSSCs) are proposed by modifying highly transparent and highly ordered multilayer mesoporous TiO2 photoanodes through nitrogen-doping and top-coating with a light-scattering layer. The mesoporous TiO2 photoanodes were fabricated by an evaporation-induced self-assembly method. In regard to the modification methods, the light-scattering layer as a top-coating was proved to be superior to nitrogen-doping in enhancing not only the power conversion efficiency but also the fill factor of DSSCs. The optimized bifunctional photoanode consisted of a 30-layer mesoporous TiO2 thin film (4.15 mm) and a Degussa P25 light-scattering top-layer (4 mm), which …


Investigation Of The Hydrogen Storage Mechanism Of Expanded Graphite By Measuring Electrical Resistance Changes, Ji Sun Im, Seungsoon Jang, Youngseak Lee Jan 2012

Investigation Of The Hydrogen Storage Mechanism Of Expanded Graphite By Measuring Electrical Resistance Changes, Ji Sun Im, Seungsoon Jang, Youngseak Lee

Australian Institute for Innovative Materials - Papers

The hydrogen storage mechanism of graphite was studied by measuring the electrical resistance change. Graphite was expanded and activated to allow for an easy hydrogen molecule approach and to enlarge the adsorption sites. A vanadium catalyst was simultaneously introduced on the graphite during the activation process. The hydrogen storage increased due to the effects of expansion, activation, and the catalyst. In addition, the electrical resistance of the prepared samples was measured during hydrogen molecule adsorption to investigate the hydrogen adsorption mechanism. It was found that the electrical resistance changed as a result of the easy hydrogen molecule approach, as well …


Temperature And Frequency Dependent Giant Magnetodielectric Coupling In Dymn0.33fe0.67o3, Fang Hong, Zhenxiang Cheng, Xiaolin Wang Jan 2012

Temperature And Frequency Dependent Giant Magnetodielectric Coupling In Dymn0.33fe0.67o3, Fang Hong, Zhenxiang Cheng, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

Perovskite DyMn0.33Fe0.67O3 experiences a paramagnetism-antiferromagnetism transition at 450K and spin reorientation at 290 K. Magnetodielectric properties were studied around the spin reorientation transition. Both giant positive and giant negative magnetodielectric coupling (MDC) were observed near room temperature. The MDC shows strong temperature and frequency dependence, and the sign changes from positive to negative when magnetic state transits from a canted antiferromagnetic state to a collinear antiferromagnetic state. Possible mechanisms are proposed based on the Maxwell-Wagner model, phase transition, the magnetoresistance effect, and spin-phonon coupling.


Effects Of Atomic Layer Deposited Thin Films On Dye Sensitized Solar Cell Performance, Jonathan A. Campbell, Mervyn Deborniol, Attila J. Mozer, Peter J. Evans, Robert P. Burford, Gerry Triani Jan 2012

Effects Of Atomic Layer Deposited Thin Films On Dye Sensitized Solar Cell Performance, Jonathan A. Campbell, Mervyn Deborniol, Attila J. Mozer, Peter J. Evans, Robert P. Burford, Gerry Triani

Australian Institute for Innovative Materials - Papers

"The application of thin titania films by atomic layer deposition on top of a low temperature nanoparticulate TiO2 electrode was found to enhance the performance of dye sensitized solar cells. Dynamic measurements of photoinduced charge extraction showed that the atomic layer deposited top coat increased the electron lifetime at the same electron density. This was attributed to an increased electron trap concentration, which resulted in slower charge transport and increased charge carrier lifetimes.


Flux Distribution In Fe-Based Superconducting Materials By Magneto-Optical Imaging, Zhi Wei Lin, Jian Guo Zhu, You Guang Guo, Xiaolin Wang, S X. Dou, Tom H. Johansen, Xun Shi, K Y. Choi Jan 2012

Flux Distribution In Fe-Based Superconducting Materials By Magneto-Optical Imaging, Zhi Wei Lin, Jian Guo Zhu, You Guang Guo, Xiaolin Wang, S X. Dou, Tom H. Johansen, Xun Shi, K Y. Choi

Australian Institute for Innovative Materials - Papers

"This paper presents the magnetic flux distributions in Fe-based superconducting materials including single crystal of Ba(Fe1.9Ni0.1)As2 and Ba(Fe1.8Co0.2)As2, as well as polycrystalline SmFeO0.75F0.2As by means of magneto-optical imaging (MOI) technique. The single crystals were grown out of FeAs flux while polycrystalline sample was grown by hot-press. A MOI film with in-plan magnetization was used to visualize flux distributions at the sample surface. A series of magneto-optical images was taken when the samples were zero-field cooled and field cooled. The flux behavior, including penetration into and …