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Full-Text Articles in Engineering

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.


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 …


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 …


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 …


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. …


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.


Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten Jan 2012

Electrically Conductive, Tough Hydrogels With Ph Sensitivity, Sina Naficy, Joselito M. Razal, Geoffrey M. Spinks, Gordon G. Wallace, Philip G. Whitten

Australian Institute for Innovative Materials - Papers

Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm-1. This conductivity is the highest yet reported …


Strain Modulated Transient Photostriction In La And Nb Codoped Multiferroic Bifeo3 Thin Films, Zuanming Jin, Yue Xu, Zhengbing Zhang, Xian Lin, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang Jan 2012

Strain Modulated Transient Photostriction In La And Nb Codoped Multiferroic Bifeo3 Thin Films, Zuanming Jin, Yue Xu, Zhengbing Zhang, Xian Lin, Guohong Ma, Zhenxiang Cheng, Xiaolin Wang

Australian Institute for Innovative Materials - Papers

The coherent longitudinal acoustic (LA) phonons in La and Nb codoped polycrystalline BiFeO3 (Bi0.8La0.2Fe 0.99Nb0.01O3 (BLFNO)) films are photo-induced and detected by the ultrafast reflectance spectroscopy. The generation mechanism of LA phonons is strongly connected with the ferroelectric polarization and is attributed to the transient photostriction effect, which is a combination of the optical rectification effect and the electrostriction effect. The strain modulation of sound velocity and out-of-plane elastic properties are demonstrated in BLFNO film on SrTiO3, which gives the insight on the dynamical coupling between electrical polarization and lattice deformation. Our findings are desired for the design of BiFeO3-based …


Material Characterization At Low Frequencies Using Thz And Raman Spectroscopy, Y Kutuvantavida, G V M Williams, E M. Pogson, D Bhuiyan, K Radhanpura, Roger A. Lewis Jan 2012

Material Characterization At Low Frequencies Using Thz And Raman Spectroscopy, Y Kutuvantavida, G V M Williams, E M. Pogson, D Bhuiyan, K Radhanpura, Roger A. Lewis

Australian Institute for Innovative Materials - Papers

We present results from wideband THz, low wave-number Raman, and FTIR measurements on benzoic acid and two of its derivatives. The low energy vibrational modes have been identified and compared with the results from calculations.


The Geologic Turn: Architecture's New Alliance, Etienne Turpin Jan 2012

The Geologic Turn: Architecture's New Alliance, Etienne Turpin

SMART Infrastructure Facility - Papers

Recent research and practice in the fields of architecture, art, and philosophy suggest the increasing influence of geology with the design disciplines, visual arts, and theoretical humanities. The symposium A Geologic Turn: Architecture's New Alliance, curated by Etienne Turpin, Ph.D., as part of the Sanders Research Fellowship at the Taubman College of Architecture & Urban Planning, University of Michigan, bring together researchers, scholars, and practitioners whose work is at the center of this fecund transdisciplinary trajectory. The objectives of the symposium are to encourage new productive connections among current scholarship and practice, and to expose this new transdisciplanary research to …


Waypoints On A Journey Of Discovery: Mental Models In Human Environment Interactions, Timothy Lynam, Raphael Mathevet, Michel Etienne, Samantha Stone-Jovicich, Anne Leitch, Nathalie Jones, Helen Ross, Derick Du Toit, Sharon Pollard, Harry Biggs, Pascal Perez Jan 2012

Waypoints On A Journey Of Discovery: Mental Models In Human Environment Interactions, Timothy Lynam, Raphael Mathevet, Michel Etienne, Samantha Stone-Jovicich, Anne Leitch, Nathalie Jones, Helen Ross, Derick Du Toit, Sharon Pollard, Harry Biggs, Pascal Perez

SMART Infrastructure Facility - Papers

Although the broad concept of mental models is gaining currency as a way to explore the link between how people think and interact with their world, this concept is limited by a theoretical and practical understanding of how it can be applied in the study of human-environment relationships. Tools and processes are needed to be able to elicit and analyze mental models. Because mental models are not directly observable, it is also important to understand how the application of any tools and processes affects what is measured. Equally important are the needs to be clear on the intent of the …


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.


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 …


Enhanced Hydrogen Storage Properties Of Naalh4 Co-Catalysed With Niobium Fluoride And Single-Walled Carbon Nanotubes, Jianfeng Mao, Zaiping Guo, Hua-Kun Liu Jan 2012

Enhanced Hydrogen Storage Properties Of Naalh4 Co-Catalysed With Niobium Fluoride And Single-Walled Carbon Nanotubes, Jianfeng Mao, Zaiping Guo, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

The effects of single-walled carbon nanotubes (SWCNTs) as a co-catalyst with NbF5 on the dehydrogenation and hydrogenation kinetics of NaAlH4 were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, temperature-programmed desorption, and isothermal hydrogen ab/desorption techniques. It has been revealed that there is a synergistic effect of SWCNTs and NbF5 on the de/rehydrogenation of NaAlH4, which improves the hydrogen de/absorption performance when compared to adding either SWCNTs or NbF5 alone. For example, the apparent activation energy for the first-step and the second-step dehydrogenation of the co-doped NaAlH4 sample is estimated to be 85.9 …


Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou Jan 2012

Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou

Australian Institute for Innovative Materials - Papers

YFeO3 single crystal displays two relaxor-like dielectric relaxations, one at low temperature (170300 K) and one at high temperature (370520 K), which are attributed to the activation of electrons and oxygen vacancies, respectively. Above the temperature at which electrons are activated, the sample displays a large magnetocapacitance effect. Comparison of the impedance Cole-Cole plots measured with and without applied magnetic field reveals that the occurrence of magnetocapacitance effect is accompanied with an increasing in DC conductivity under magnetic field after the activation of electrons, which is explained by the enhancement of electron jumping in Fe2b-O-Fe3b chains by magnetic field. Thus …


Large Scale Synthesis Of V-Shaped Rutile Twinned Nanorods, Weigang Lu, Britain Bruner, Gilberto Casillas, Jibao He, Miguel Jose-Yacaman, Patrick J. Farmer Jan 2012

Large Scale Synthesis Of V-Shaped Rutile Twinned Nanorods, Weigang Lu, Britain Bruner, Gilberto Casillas, Jibao He, Miguel Jose-Yacaman, Patrick J. Farmer

Australian Institute for Innovative Materials - Papers

V-shaped rutile twinned nanorods (VRTNs) with different aspect ratios were synthesized on large scale using a one-pot organic solvothermal method. Although several different types of VRTNs were produced, (101) twinned nanorods were the major product with minor amounts of (301) twins and straight nanorods. STEM, TEM and XRD characterizations show that [001] is the growth direction of VRTNs, with surfaces dominated by {110} facets. Intermediate formation of both brookite and anatase nanorods provides dual pathways to VRTNs’ growth: one path in which anatase seeds trigger and promote brookite nanorod growth; and a second path in which anatase nanorods are formed …


Power To You: Carbon Nanotube Muscles Are Going Strong, Geoffrey M. Spinks Jan 2012

Power To You: Carbon Nanotube Muscles Are Going Strong, Geoffrey M. Spinks

Australian Institute for Innovative Materials - Papers

Just on a year ago my colleagues and I announced our discovery that carbon nanotube yarns could be made to twist and rotate at great speeds when electrically stimulated. In this way we had created "artificial muscles" that could change their shape in response to stimulus.


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.


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. …


An Efficient Way To Enhance Output Strain For Shear Mode Pb(In1/2nb1/2)O-3-Pb(Mg1/3nb2/3)O-3-Pbtio3 Crystals: Applying Uniaxial Stress Perpendicular To Polar Direction, Fei Li, Shujun Zhang, Zhuo Xu, Dabin Lin, Junjie Gao, Zhenrong Li, Linghang Wang Jan 2012

An Efficient Way To Enhance Output Strain For Shear Mode Pb(In1/2nb1/2)O-3-Pb(Mg1/3nb2/3)O-3-Pbtio3 Crystals: Applying Uniaxial Stress Perpendicular To Polar Direction, Fei Li, Shujun Zhang, Zhuo Xu, Dabin Lin, Junjie Gao, Zhenrong Li, Linghang Wang

Australian Institute for Innovative Materials - Papers

The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with "1T" and "2R" domain configurations, respectively, were investigated under uniaxial stress perpendicular to polar direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both "1T" and "2R" crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to polar direction, resulting in a "harder" polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was …


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 …


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 …


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, …