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Articles 1291 - 1320 of 1524

Full-Text Articles in Physical Sciences and Mathematics

Giant Interlayer Magnetoresistances And Strong Anisotropy In P-Type Sb2te3 Single Crystals, Zengji Yue, Xiaolin Wang, S X. Dou Jan 2012

Giant Interlayer Magnetoresistances And Strong Anisotropy In P-Type Sb2te3 Single Crystals, Zengji Yue, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

Anisotropic interlayer magneto-transport properties have been studied over a broad range of temperatures and magnetic fields in p-type Sb2Te3 single crystals. Giant interlayer magnetoresistance (MR) of up to 400% was observed, which exhibits quadratic field dependences in low fields and becomes linear at high fields without any trend towards saturation. The interlayer MR displays strong anisotropy and is attributable to the anisotropy of the Fermi surface. The observed giant anisotropic interlayer MR could find applications in p-type Sb2Te3 based magneto-electronic devices.


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 Multimodal Optical And Electrochemical Device For Monitoring Surface Reactions: Redox Active Surfaces In Porous Silicon Rugate Filters, Simone Ciampi, Bin Guan, Nadim A. Darwish, Ying Zhu, Peter J. Reece, J Justin Gooding Jan 2012

A Multimodal Optical And Electrochemical Device For Monitoring Surface Reactions: Redox Active Surfaces In Porous Silicon Rugate Filters, Simone Ciampi, Bin Guan, Nadim A. Darwish, Ying Zhu, Peter J. Reece, J Justin Gooding

Australian Institute for Innovative Materials - Papers

Herein, mesoporous silicon (PSi) is configured as a single sensing device that has dual readouts; as a photonic crystal sensor in a Rugate filter configuration, and as a high surface area porous electrode. The as-prepared PSi is chemically modified to provide it with stability in aqueous media and to allow for the subsequent coupling of chemical species, such as via Cu(i)-catalyzed cycloaddition reactions between 1-alkynes and azides ("click" reactions). The utility of the bimodal capabilities of the PSi sensor for monitoring surface coupling procedures is demonstrated by the covalent coupling of a ferrocene derivative, as well as by demonstrating ligand-exchange …


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 …


Fabrication And Magneto-Transport Properties Of P-Type Bi0.5sb1.5te3 Thin Films On Glass By Pulsed Laser Deposition, Zhenwei Yu, Xiaolin Wang, Yi Du, Chao Zhang Jan 2012

Fabrication And Magneto-Transport Properties Of P-Type Bi0.5sb1.5te3 Thin Films On Glass By Pulsed Laser Deposition, Zhenwei Yu, Xiaolin Wang, Yi Du, Chao Zhang

Australian Institute for Innovative Materials - Papers

Bi0.5Sb1. 5Te3 thin films were deposited on glass substrates by pulsed laser deposition (PLD) method at room temperature. Annealing effect on properties of the films was studied by structural, morphology and physical characterizations. It was found that the as-grown amorphous film crystallizes at annealing temperature of 473 K. A semiconductor-metal transition was observed in annealed films. A linear magnetoresistance (MR) was investigated in the annealed films in a magnetic field up to 13 T without saturation at low temperature.


Positive And Negative Exchange Bias Effects In The Simple Perovskite Manganite Ndmno3, Fang Hong, Zhenxiang Cheng, Jianli Wang, Xiaolin Wang, S X. Dou Jan 2012

Positive And Negative Exchange Bias Effects In The Simple Perovskite Manganite Ndmno3, Fang Hong, Zhenxiang Cheng, Jianli Wang, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

Exchange bias effects were studied in the simple perovskite NdMnO 3. Nd 3+ ordering is induced by the Mn 3+ ferromagnetic component, and they are antiferromagnetically coupled with each other. At 30 K, both negative and positive exchange bias effects are found, which are dependent on the cooling field. The exchange bias fields are around -2400 Oe and 1800 Oe, respectively. Positive and negative exchange bias effects were also observed at 8 K, but the exchange bias fields are only 130 Oe and -120 Oe. The coupling intensity between Nd 3+ ordering and Mn 3+ ordering, and their initial states …


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 …


Exchange Bias In A Nanocrystalline Hematite/Permalloy Thin Film Investigated With Polarized Neutron Reflectometry, David Laurence Cortie, K. -W Lin, H. - F. Hsu, X L. Wang, M James, H Fritzsche, S Bruck, F Klose Jan 2012

Exchange Bias In A Nanocrystalline Hematite/Permalloy Thin Film Investigated With Polarized Neutron Reflectometry, David Laurence Cortie, K. -W Lin, H. - F. Hsu, X L. Wang, M James, H Fritzsche, S Bruck, F Klose

Australian Institute for Innovative Materials - Papers

We investigated a hematite α-Fe2O3/permalloy Ni80Fe20 bilayer film where the antiferromagnetic layer consisted of small hematite grains in the 2 to 16 nm range. A pronounced exchange bias effect occurred below the blocking temperature of 40 K. The magnitude of exchange bias was enhanced relative to reports for identical compounds in large grain, epitaxial films. However, the blocking temperature was dramatically reduced. As the Néel temperature of bulk α-Fe2O3 is known to be very high (860 K), we attribute the low-temperature onset of exchange bias to the well-known finite-size effect which suppresses the Morin transition for nanostructured hematite. Polarized neutron …


Optical Parameters Of Znte Determined Using Continuous-Wave Terahertz Radiation, E Constable, Roger A. Lewis Jan 2012

Optical Parameters Of Znte Determined Using Continuous-Wave Terahertz Radiation, E Constable, Roger A. Lewis

Australian Institute for Innovative Materials - Papers

The optical parameters of three ZnTe crystal wafers of different thicknesses were determined using transmittance measurements of continuous-wave terahertz radiation from a two-color photomixing source. The parameters are extracted by fitting the transmittance data with theoretical curves generated using a Drude-Lorentz dielectric model of the crystal and a bootstrap statistical analysis of the fits. It was found at room temperature that the low and high frequency dielectric constants are ϵ(0) = 9.8±0.2 and ϵ(∞) = 7.3±0.6, respectively. The transverse optical phonon frequency was found to be νTO = 6.0±1.3 THz. Sample specific properties such as the plasma, collision, and phonon …


Parameters Controlling Emission Of Terahertz Frequency Electromagnetic Radiation From Inas And Gaas: An Ensemble Monte Carlo Simulation Study, David Laurence Cortie, Roger A. Lewis Jan 2012

Parameters Controlling Emission Of Terahertz Frequency Electromagnetic Radiation From Inas And Gaas: An Ensemble Monte Carlo Simulation Study, David Laurence Cortie, Roger A. Lewis

Australian Institute for Innovative Materials - Papers

The generation, manipulation and detection of terahertz-frequency electromagnetic radiation are topics of great current theoretical and experimental interest. In particular, the coherent generation and detection of ultrashort pulses of terahertz radiation has opened up the field of terahertz time-domain spectroscopy, which permits the simultaneous measurement of amplitude and phase of the terahertz electric field. In this paper, the emission of terahertz radiation from bare semiconductor surfaces following photoexcitation by ultrashort pulses of near-infrared radiation is studied using ensemble Monte Carlo simulations. The simulation allows us to examine separately distinct scattering mechanisms and to vary the materials parameters of bandgap, absorption …


Physicochemical Study Of Spiropyran-Terthiophene Derivatives: Photochemistry And Thermodynamics, Michele Zanoni, Simon Coleman, Kevin J. Fraser, Robert P. Byrne, Klaudia K. Wagner, Sanjeev Gambhir, David L. Officer, Gordon G. Wallace, D Diamond Jan 2012

Physicochemical Study Of Spiropyran-Terthiophene Derivatives: Photochemistry And Thermodynamics, Michele Zanoni, Simon Coleman, Kevin J. Fraser, Robert P. Byrne, Klaudia K. Wagner, Sanjeev Gambhir, David L. Officer, Gordon G. Wallace, D Diamond

Australian Institute for Innovative Materials - Papers

The photochemistry and thermodynamics of two terthiophene (TTh) derivatives bearing benzospiropyran (BSP) moieties, 1-(3,3''-dimethylindoline-6'-nitrobenzospiropyranyl)-2-ethyl 4,4''-didecyloxy-2,2':5',2''-terthiophene-30-acetate (BSP-2) and 1-(3,3''-dimethylindoline-6'- nitrobenzospiropyranyl)-2-ethyl 4,4''-didecyloxy-2,2':5',2''-terthiophene-30-carboxylate (BSP-3), differing only by a single methylene spacer unit, have been studied. The kinetics of photogeneration of the equivalent merocyanine (MC) isomers (MC-2 and MC-3, respectively), the isomerisation properties of MC-2 and MC-3, and the thermodynamic parameters have been studied in acetonitrile, and compared to the parent, non-TTh-functionalised, benzospiropyran derivative, BSP-1. Despite the close structural similarity of BSP-2 and BSP-3, their physicochemical properties were found to differ significantly; examples include activation energies (Ea(MC-2) = 75.05 kJ mol-1, …


Actuating Individual Electrospun Hydrogel Nanofibres, Adrian Gestos, Philip G. Whitten, Gordon G. Wallace, Geoffrey Maxwell Spinks Jan 2012

Actuating Individual Electrospun Hydrogel Nanofibres, Adrian Gestos, Philip G. Whitten, Gordon G. Wallace, Geoffrey Maxwell Spinks

Australian Institute for Innovative Materials - Papers

The actuation of a single hydrogel nanofibre is measured for the first time by AFM. The actuation stress generated was comparable to that produced by skeletal muscle and the actuation rate was significantly increased by the nanoscale dimensions of the fibre.


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 …


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 …


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 …


Polypyrrole Coated Nylon Lycra Fabric As Stretchable Electrode For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace Jan 2012

Polypyrrole Coated Nylon Lycra Fabric As Stretchable Electrode For Supercapacitor Applications, Binbin Yue, Caiyun Wang, Xin Ding, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Wearable electronics offer the combined advantages of both electronics and fabrics. Being an indispensable part of these electronics, lightweight, stretchable and wearable power sources are strongly demanded. Here we describe a daily-used nylon lycra fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the fabric via a simple chemical polymerization process with ammonium persulfate (APS) as an oxidant and naphthalene-2,6-disulfonic acid disodium salt (Na2NDS) as a dopant. This material was characterized with FESEM, FTIR, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile could endure 1000 stretching cycles …


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.


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).


Anti And Gauche Conformers Of An Inorganic Butane Analogue, Nh3bh2nh2bh3, Xuenian Chen, Judith C. Gallucci, Charles Campana, Zhenguo Huang, Hima Kumar Lingam, Sheldon G. Shore, Ji-Cheng Zhao Jan 2012

Anti And Gauche Conformers Of An Inorganic Butane Analogue, Nh3bh2nh2bh3, Xuenian Chen, Judith C. Gallucci, Charles Campana, Zhenguo Huang, Hima Kumar Lingam, Sheldon G. Shore, Ji-Cheng Zhao

Australian Institute for Innovative Materials - Papers

The crystal structures of an inorganic butane analogue, NH3BH2NH2BH3 (DDAB), were determined using single crystal X-ray diffraction, revealing both anti and gauche conformations. The anti conformation is stabilized by intermolecular dihydrogen bonds in the crystal whereas two gauche conformations of DDAB observed in its 18-crown-6 adducts are stabilized by an intramolecular dihydrogen bond. The two gauche conformations show rotational isomerization but whether they are a pair of enantiomers is yet to be defined.


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.


Hollow Nitrogen Containing Core/Shell Fibrous Carbon Nanomaterials As Support To Platinum Nanocatalysts And Their Tem Tomography Study, Cuifeng Zhou, Zongwen Liu, Xusheng Du, David Rg Mitchell, Yiu-Wing Mai, Yushan Yan, Simon Peter Ringer Jan 2012

Hollow Nitrogen Containing Core/Shell Fibrous Carbon Nanomaterials As Support To Platinum Nanocatalysts And Their Tem Tomography Study, Cuifeng Zhou, Zongwen Liu, Xusheng Du, David Rg Mitchell, Yiu-Wing Mai, Yushan Yan, Simon Peter Ringer

Australian Institute for Innovative Materials - Papers

Core/shell nanostructured carbon materials with carbon nanofiber (CNF) as the core and a nitrogen (N)-doped graphitic layer as the shell were synthesized by pyrolysis of CNF/polyaniline (CNF/PANI) composites prepared by in situ polymerization of aniline on CNFs. High-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared and Raman analyses indicated that the PANI shell was carbonized at 900 degress C. Platinum (Pt) nanoparticles were reduced by formic acid with catalyst supports. Compared to the untreated CNF/ PANI composites, the carbonized composites were proven to be better supporting materials for the Pt nanocatalysts and showed superior performance as catalyst …


The Problem Of Road Congestion: The Fultility Of 'Avoidable Cost' Estimates, Mark D. Harrison Jan 2012

The Problem Of Road Congestion: The Fultility Of 'Avoidable Cost' Estimates, Mark D. Harrison

Australian Institute for Innovative Materials - Papers

The Bureau of Infrastructure, Transport and Regional Economics estimates of the costs of road congestion in Australian capital cities ($9.4 billion in 2005 and projected to more than double by 2020) are widely cited. But these projections appear to overstate the problem and provide little, if any, guidance for sound policy development. They are not measures of the net gain from introducing congestion charging. Moreover, such numbers provide no help for evaluating the net benefits of other policies to deal with congestion, such as increasing road capacity. Without efficiency-based cost-benefit analysis of all policies to deal with road congestion, governments …


Electroacoustic Response Of 1-3 Piezocomposite Transducers For High Power Applications, Hyeong Jae Lee, Shujun Zhang, Xuecang Geng, Thomas R. Shrout Jan 2012

Electroacoustic Response Of 1-3 Piezocomposite Transducers For High Power Applications, Hyeong Jae Lee, Shujun Zhang, Xuecang Geng, Thomas R. Shrout

Australian Institute for Innovative Materials - Papers

The electroacoustic performance of 1-3 piezoelectric composite transducers with low loss polymer filler was studied and compared to monolithic Pb(Zr,Ti)O 3 (PZT) piezoelectric transducers. The 1-3 composite transducers exhibited significantly high electromechanical coupling factor (k t ∼ 0.64) when compared to monolithic counterparts (k t ∼ 0.5), leading to the improved bandwidth and loop sensitivity, being on the order of 67% and -24.0 dB versus 44% and -24.8 dB, respectively. In addition, the acoustic output power and transmit efficiency (∼50%) were found to be comparable to the monolithic PZT transducers, demonstrating potential for broad bandwidth, high power ultrasonic transducer applications.


High Performance Ferroelectric Relaxor-Pbtio3 Single Crystals: Status And Perspective, Shujun Zhang, Fei Li Jan 2012

High Performance Ferroelectric Relaxor-Pbtio3 Single Crystals: Status And Perspective, Shujun Zhang, Fei Li

Australian Institute for Innovative Materials - Papers

Ferroelectrics are essential components in a wide range of applications, including ultrasonic transducers, sensors, and actuators. In the single crystal form, relaxor-PbTiO3 (PT) piezoelectric materials have been extensively studied due to their ultrahigh piezoelectric and electromechanical properties. In this article, a perspective and future development of relaxor-PT crystals are given. Initially, various techniques for the growth of relaxor-PT crystals are reviewed, with crystals up to 100 mm in diameter and 200 mm in length being readily achievable using the Bridgman technique. Second, the characterizations of dielectric and electromechanical properties are surveyed. Boundary conditions, including temperature, electric field, and stress, are …