Physical Sciences and Mathematics Commons^™

One-Dimensional Manganese-Cobalt Oxide Nanofibres As Bi-Functional Cathode Catalysts For Rechargeable Metal-Air Batteries, Kyu-Nam Jung, Soomin Hwang, Min-Sik Park, Ki Jae Kim, Jae-Geun Kim, S X. Dou, Jung Ho Kim, Jongwon Lee

Australian Institute for Innovative Materials - Papers

Rechargeable metal-air batteries are considered a promising energy storage solution owing to their high theoretical energy density. The major obstacles to realising this technology include the slow kinetics of oxygen reduction and evolution on the cathode (air electrode) upon battery discharging and charging, respectively. Here, we report non-precious metal oxide catalysts based on spinel-type manganese-cobalt oxide nanofibres fabricated by an electrospinning technique. The spinel oxide nanofibres exhibit high catalytic activity towards both oxygen reduction and evolution in an alkaline electrolyte. When incorporated as cathode catalysts in Zn-air batteries, the fibrous spinel oxides considerably reduce the discharge-charge voltage gaps (improve the …

Porous Amorphous Ge/C Composites With Excellent Electrochemical Properties, Xiu Li, Wei Guo, Qian Wan, Jianmin Ma

Australian Institute for Innovative Materials - Papers

Porous amorphous germanium/carbon (Ge/C) composites, which were synthesized through the reduction/carbonization of germanium oxide/oleic acid precursors, could exhibit a high-capacity, high-rate and long-life performance due to the synergistic effect of the porous structure and carbon.

Electrical Stimulation Using Conductive Polymer Polypyrrole Promotes Differentiation Of Human Neural Stem Cells: A Biocompatible Platform For Translational Neural Tissue Engineering, Elise Stewart, Nao R. Kobayashi, Michael J. Higgins, Anita Quigley, Sina S. Jamali, Simon Moulton, Robert M. I Kapsa, Gordon G. Wallace, Jeremy M. Crook

Australian Institute for Innovative Materials - Papers

Conductive polymers (CPs) are organic materials that hold great promise for biomedicine. Potential applications include in vitro or implantable electrodes for excitable cell recording and stimulation, and conductive scaffolds for cell support and tissue engineering. Here we demonstrate the utility of electroactive CP Polypyrrole (PPy) containing the anionic dopant dodecylbenzenesulfonate (DBS) to differentiate novel clinically relevant human neural stem cells (hNSCs). Electrical stimulation of PPy(DBS) induced hNSCs to predominantly β-III Tubulin (Tuj1) expressing neurons, with lower induction of glial fibrillary acidic protein (GFAP) expressing glial cells. In addition, stimulated cultures comprised nodes or clusters of neurons with longer neurites and …

Split-Half-Tubular Polypyrrole@Sulfur@Polypyrrole Composite With A Novel Three-Layer-3d Structure As Cathode For Lithium/Sulfur Batteries, Xin Liang, Mingang Zhang, Mohammad Kaiser, Xuanwen Gao, Konstantin Konstantinov, Richard Tandiono, Zhaoxiang Wang, Hua-Kun Liu, S X. Dou, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

Polypyrrole@Sulfur@Polypyrrole composite with a novel three-layer-3D-structure, which consists of an external polypyrrole coating layer, an intermediate sulfur filling layer, and an internal polypyrrole split-half-tube conducting matrix layer, has been synthesized by the oxidative chemical polymerization method and chemical precipitation method in this article. Due to this unique three-layer-structure, the discharge specific capacity of Polypyrrole@Sulfur@Polypyrrole composite cathode retained at 554mAh g-1 after 50 cycles, which represents 68.8% retention of the initial discharge specific capacity. In comparison, the Sulfur@Polypyrrole composite cathode, with the same components as Polypyrrole@Sulfur@Polypyrrole composite, but without the three-layer-structure, has the discharge specific capacity of 370mAh g-1 after 50 …

Processable Conducting Graphene/Chitosan Hydrogels For Tissue Engineering, Sepidar Sayyar, Eoin Murray, Brianna Thompson, Johnson Chung, David L. Officer, Sanjeev Gambhir, Geoffrey M. Spinks, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Composites of graphene in a chitosan-lactic acid matrix were prepared to create conductive hydrogels that are processable, exhibit tunable swelling properties and show excellent biocompatibility. The addition of graphene to the polymer matrix also resulted in significant improvements to the mechanical strength of the hydrogels, with the addition of just 3 wt% graphene resulting in tensile strengths increasing by over 200%. The composites could be easily processed into three-dimensional scaffolds with finely controlled dimensions using additive fabrication techniques and fibroblast cells demonstrate good adhesion and growth on their surfaces. These chitosan-graphene composites show great promise for use as conducting substrates …

Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu

Australian Institute for Innovative Materials - Papers

Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu2-xSe, with figure of merit, zT, over 1.5 at T of ~ 1000 K, should meet these requirements, based on our analysis of its crystal structure and the Cu-Se binary phase diagram. We found that its excellent thermoelectric performance is intrinsic, and less dependent on grain size, while highly dense samples can …

Poly(3,4-Ethylenedioxythiophene): Dextran Sulfate (Pedot: Ds) - A Highly Processable Conductive Organic Biopolymer, David Harman, Robert Gorkin Iii, Leo Stevens, Brianna Thompson, Klaudia Wagner, Bo Weng, Johnson Chung, Marc In Het Panhuis, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

A novel water-dispersible conducting polymer analogous to poly(3,4-dioxythiophene):polystyrene sulfonate (PEDOT:PSS) has been chemically synthesized in a single reaction in high yield. PEDOT:DS, a new member of the polythiophene family, is composed of a complex between PEDOT and the sulfonated polysaccharide polyanion dextran sulfate. Drop-cast films of aqueous suspensions of the material display a native conductivity of up to 7 ± 1 S cm^-1, increasing to 20 ± 2 S cm^-1 after treatment with ethylene glycol and thermal annealing. Mass ratios of the precursors NaDS and EDOT were varied from 5:1 to 2:1 and a decrease in the …

Mesoporous Hierarchical Anatase For Dye-Sensitized Solar Cells Achieving Over 10% Conversion Efficiency, Jianjian Lin, Yoon-Uk Heo, Andrew Nattestad, Yusuke Yamauchi, S X. Dou, Jung Ho Kim

Australian Institute for Innovative Materials - Papers

Interest in both one-dimensional and hierarchical architectures of metal oxide semiconductors has intensified within the field of materials science over recent years. Herein, a new mesoporous anatase TiO₂ architecture that combines these two concepts, as it is composed of individual, high-aspect-ratio, nanoribbon-like components, was synthesized via a facile hydrothermal method without any surfactant or template. An 8.3% solar-to-electric conversion efficiency was obtained when these structures were used in photoanodes for dye-sensitized solar cells, which are superior to commercial state-of-the-art TiO₂ (6.6%), due to enhanced dye loading and efficient light scattering. To further improve the light scattering effect, a …

Next Generation Bioelectronics: Advances In Fabrication Coupled With Clever Chemistries Enable The Effective Integration Of Biomaterials And Organic Conductors, Paul Molino, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Organic bioelectronics is making an enormous impact in the field of tissue engineering, providing not just biocompatible, but biofunctional conducting material platforms. For their true potential to be reached, it is critical to integrate organic conductors with other biopolymers in a targeted manner, allowing the development of devices and scaffold architectures capable of delivering a number of physical, chemical, and electrical stimuli. Herein, we provide an overview of the methods currently being employed to tailor organic conductors for bioapplications, with a focus on the development of fabrication techniques vital to the development of the next generation of intelligent bionic devices.

Magnetocaloric Effect And Magnetostructural Coupling In Mn0.92fe0.08coge Compound, Jianli Wang, Precious Shamba, Wayne D. Hutchison, Qinfen Gu, M F. Md Din, Q Y. Ren, Zhenxiang Cheng, Shane J. Kennedy, Stewart J. Campbell, S X. Dou

Australian Institute for Innovative Materials - Papers

The structural properties of Mn_0.92Fe_0.08CoGe have been investigated in detail using synchrotron x-ray diffraction in zero and applied pressure (p = 0-10 GPa). A ferromagnetic transition occurs around T_C = 300 K and a large magnetic-entropy change −ΔS_M = 17.3 J/kg K detected at T_C for a field change of ΔB = 5 T. The field dependence of −ΔS _M ^max can be expressed as −ΔS _M ^max ∝ B. At ambient temperature and pressure, Mn_0.92Fe_0.08CoGe exhibits a co-existence of the orthorhombic TiNiSi-type structure (space group Pnma) and hexagonal …

Hydrostatic Pressure: A Very Effective Approach To Significantly Enhance Critical Current Density In Granular Iron Pnictide Superconductors, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, C Shekhar, S X. Dou, O.N Srivastava

Australian Institute for Innovative Materials - Papers

Pressure is well known to significantly raise the superconducting transition temperature, T_c, in both iron pnictides and cuprate based superconductors. Little work has been done, however, on how pressure can affect the flux pinning and critical current density in the Fe-based superconductors. Here, we propose to use hydrostatic pressure to significantly enhance flux pinning and T_c in polycrystalline pnictide bulks. We have chosen Sr₄V₂O₆Fe₂As₂ polycrystalline samples as a case study. We demonstrate that the hydrostatic pressure up to 1.2 GPa can not only significantly increase T_c from …

Anomalies In Magnetoelastic Properties Of Dyfe11.2nb0.8 Compound, Jianli Wang, M F. Md Din, Shane J. Kennedy, Zhenxiang Cheng, Stewart J. Campbell, Justin A. Kimpton, S X. Dou

Australian Institute for Innovative Materials - Papers

The structural and magnetic properties of DyFe_11.2Nb_0.8 compound have been investigated by high intensity, high resolution synchrotron x-ray diffraction, ac magnetic susceptibility, and dc magnetization measurements as well as Mössbauer spectroscopy (5-300 K). The easy magnetization direction at room temperature is along the c-axis. With decreasing temperature, the magnetocrystalline anisotropy changes from easy-axis to easy-cone at T_sr2 (∼202 K), then to easy plane at T_sr1 (∼94 K). The thermal expansion coefficient obtained from the synchrotron x-ray study exhibits clear anomalies around both of the spin reorientation transition temperatures. The ⁵⁷Fe hyperfine interaction parameters and …

The Potential Of Induced Pluripotent Stem Cells In Models Of Neurological Disorders: Implications On Future Therapy, Jeremy M. Crook, Gordon G. Wallace, Eva Tomaskovic-Crook

Australian Institute for Innovative Materials - Papers

There is an urgent need for new and advanced approaches to modeling the pathological mechanisms of complex human neurological disorders. This is underscored by the decline in pharmaceutical research and development efficiency resulting in a relative decrease in new drug launches in the last several decades. Induced pluripotent stem cells represent a new tool to overcome many of the shortcomings of conventional methods, enabling live human neural cell modeling of complex conditions relating to aberrant neurodevelopment, such as schizophrenia, epilepsy and autism as well as age-associated neurodegeneration. This review considers the current status of induced pluripotent stem cell-based modeling of …

Performance Modulation Of Α-Mno2 Nanowires By Crystal Facet Engineering, W Li, Xiangyuan Cui, R Zeng, Guodong Du, Ziqi Sun, Rongkun Zheng, Simon Peter Ringer, S X. Dou

Australian Institute for Innovative Materials - Papers

Modulation of material physical and chemical properties through selective surface engineering is currently one of the most active research fields, aimed at optimizing functional performance for applications. The activity of exposed crystal planes determines the catalytic, sensory, photocatalytic, and electrochemical behavior of a material. In the research on nanomagnets, it opens up new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Herein, we demonstrate controllable magnetic modulation of α-MnO₂ nanowires, which displayed surface ferromagnetism or antiferromagnetism, depending on the exposed plane. First-principles density functional theory calculations confirm that both Mn- and O-terminated α-MnO₂ (1 …

N719- And D149-Sensitized 3d Hierarchical Rutile Tio2 Solar Cells - A Comparative Study, Jianjian Lin, Yoon-Uk Heo, Andrew Nattestad, Mohammed Shahabuddin, Yusuke Yamauchi, Jung Ho Kim

Australian Institute for Innovative Materials - Papers

Poor dye loading on rutile TiO₂ is one of the chief reasons for lower solar-to-electric conversion efficiency (η) in dye-sensitized solar cells (DSCs), compared to their anatase based counterparts. Previously, we showed that similar light harvesting for both rutile and anatase was realized by using a metal-free organic indoline dye, D149 [Sci. Rep., 2014, 4, 5769]. This was in contrast to the bulk of previous studies, which employed ruthenium based N719, leading to significant differences in light harvesting. To date, there has been no report directly comparing N719 and D149 for rutile based DSCs. In this work, three-dimensional hierarchical …

Stretchable, Weavable Coiled Carbon Nanotube/Mno2/Polymer Fiber Solid-State Supercapacitors, Changsoon Choi, Shi Hyeong Kim, Hyeon Jun Sim, Jae Ah Lee, A Young Choi, Youn Tae Kim, Xavier Lepro, Geoffrey M. Spinks, Ray H. Baughman, Seon Jeong Kim

Australian Institute for Innovative Materials - Papers

Fiber and yarn supercapacitors that are elastomerically deformable without performance loss are sought for such applications as power sources for wearable electronics, micro-devices, and implantable medical devices. Previously reported yarn and fiber supercapacitors are expensive to fabricate, difficult to upscale, or non-stretchable, which limits possible use. The elastomeric electrodes of the present solid-state supercapacitors are made by using giant inserted twist to coil a nylon sewing thread that is helically wrapped with a carbon nanotube sheet, and then electrochemically depositing pseudocapacitive MnO₂ nanofibers. These solid-state supercapacitors decrease capacitance by less than 15% when reversibly stretched by 150% in the …

Facile Method To Synthesize Na-Enriched Na1+Xfefe(Cn)6 Frameworks As Cathode With Superior Electrochemical Performance For Sodium-Ion Batteries, Weijie Li, Shulei Chou, Jiazhao Wang, Yong-Mook Kang, Jianli Wang, Yong Liu, Qinfen Gu, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Different Na-enriched Na_1+xFeFe(CN)₆ samples can be synthesized by a facile one-step method, utilizing Na₄Fe(CN)₆ as the precursor in a different concentration of NaCl solution. As-prepared samples were characterized by a combination of synchrotron X-ray powder diffraction (S-XRD), Mössbauer spectroscopy, Raman spectroscopy, magnetic measurements, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma analysis. The electrochemical results show that the Na_1.56Fe[Fe(CN)₆]·3.1H₂O (PB-5) sample shows a high specific capacity of more than 100 mAh g^-1 and excellent capacity retention of 97% over 400 cycles. The details structural evolution during …

Boosting The Efficiency Of Quantum Dot Sensitized Solar Cells Up To 7.11% Through Simultaneous Engineering Of Photocathode And Photoanode, Yang Bai, Chao Han, Xinqi Chen, Hua Yu, Xu Zong, Zhen Li, Lianzhou Wang

Australian Institute for Innovative Materials - Papers

We demonstrate a new strategy of boosting the efficiency of quantum dot sensitized solar cells (QDSSCs) by engineering the photocathode and photoanode simultaneously. Nanostructured photocathodes based on non-stoichiometric Cu_2-xSe electrocatalysts were developed via a simple and scalable approach for CdS/CdSe QDs co-sensitized solar cells. Compared to Cu₂S CE, remarkably improved photovoltaic performance was achieved for QDSSCs with Cu_2-xSe CEs. The superior catalytic activity and electrical conductivity of Cu_2-xSe CEs were verified by the electrochemical impedance spectra and Tafel-polarization measurements. To maximize the efficiency enhancement, the photoanodes were optimized by introducing a pillared …

Electronic Structure And Photocatalytic Water Oxidation Activity Of Rtino2 (R = Ce, Pr And Nd) Perovskite Nitride Oxides, Spencer H. Porter, Zhenguo Huang, S X. Dou, Samantha Brown-Xu, Md. Golam Mahabub Sarwar, Roberto C. Myers, Patrick M. Woodward

Australian Institute for Innovative Materials - Papers

Three perovskite nitride oxides CeTiNO₂, PrTiNO₂, and NdTiNO₂ have been synthesized and their electronic structures and photocatalytic activities characterized and compared to LaTiNO₂. All three compounds have band gaps that fall in the range 2.0 − 2.1 eV, very similar to LaTiNO₂, which enables them to absorb a significant fraction of the visible spectrum. Photocatalytic oxygen evolution studies under visible light irradiation in the presence of a sacrificial electron acceptor (Ag⁺) show that the activity of NdTiNO₂ (16 μmol/g/hr) is comparable to that of LaTiNO₂ (17 μmol/g/hr), …

A Facile Method To Enhance Ferroelectric Properties In Pvdf Nanocomposites, Mohammad Mahdi Abolhasani, Fatemeh Zarejousheghani, Zhenxiang Cheng, Minoo Naebe

Australian Institute for Innovative Materials - Papers

Poly(vinylidene fluoride) (PVDF)/nanoclay composites were prepared using melt compounding. The effect of acrylic rubber (ACM) as a compatibilizer on different polymorph formation and on the ferroelectric properties of nanocomposites were investigated. The intercalation and morphological structure of the samples were studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The infrared spectroscopy and X-ray analysis revealed the coexistence of beta and gamma crystalline forms in PVDF-clay nanocomposite, while in partially miscible PVDF/ACM/clay hybrids, three polymorphs of alpha, beta and g coexisted. The coefficients of electric field-polarization (E-P) Taylor expansion were calculated based on the Lorentz theory. Using a genetic …

A Versatile Binder-Free Tio2 Paste For Dye-Sensitized Solar Cells, Jeremy H. Yune, Inna Karatchevtseva, P Evans, Klaudia K. Wagner, Matthew J. Griffith, David L. Officer, Gerry Triani

Australian Institute for Innovative Materials - Papers

In this study, binder-free TiO₂ colloidal pastes have been prepared using a variety of heterocyclic bases with diverse characteristics to produce robust photoanodes for dye-sensitized solar cells (DSSC) from a single cast film thickness of 5 micron. The influence of the base on the electrode structure and film morphology, including its electron donor characteristics are investigated after low temperature thermal treatment and high temperature sintering. The results show that quinoline in the TiO₂ paste is retained within the electrode structure in comparison to piperidine and pyridine after a short thermal treatment of 150 °C for 15 minutes. The …

Manganese Dioxide-Anchored Three-Dimensional Nitrogen-Doped Graphene Hybrid Aerogels As Excellent Anode Materials For Lithium Ion Batteries, Zhu Yin Sui, Caiyun Wang, Kewei Shu, Quan-Sheng Yang, Yu Ge, Gordon G. Wallace, Bao Hang Han

Australian Institute for Innovative Materials - Papers

The capacity of manganese dioxide (MnO₂) deteriorates with cycling due to the irreversible changes induced by the repeated lithiation and delithiation processes. To overcome this drawback, MnO₂/nitrogen-doped graphene hybrid aerogels (MNGAs) were prepared via a facile redox process between KMnO₄ and carbon within nitrogen-doped graphene hydrogels. The three-dimensional nitrogen-doped graphene hydrogels were prepared and utilized as matrices for MnO₂ deposition. The MNGAs-120 obtained after a deposition time of 120 min delivered a very high discharge capacity of 909 mA h g^-1 after 200 cycles at a current density of 400 mA g^{-1 …}

Efficient, Absorption-Powered Artificial Muscles Based On Carbon Nanotube Hybrid Yarns, Marcio D. Lima, Mohammad W. Hussain, Geoffrey M. Spinks, Sina Naficy, Daniela Hagenasr, Julia S. Bykova, Derrick Tolly, Ray H. Baughman

Australian Institute for Innovative Materials - Papers

A new type of absorption-powered artificial muscle provides high performance without needing a temperature change. These muscles, comprising coiled carbon nanotube fibers infiltrated with silicone rubber, can contract up to 50% to generate up to 1.2 kJ kg⁻¹. The drive mechanism for actuation is the rubber swelling during exposure to a nonpolar solvent. Theoretical energy efficiency conversion can be as high as 16%.

Reduced Graphene Oxide And Polypyrrole/Reduced Graphene Oxide Composite Coated Stretchable Fabric Electrodes For Supercapacitor Application, Chen Zhao, Kewei Shu, Caiyun Wang, Sanjeev Gambhir, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The advent of self-powered functional garments has given rise to a demand for stretchable energy storage devices that are amendable to integration into textile structures. The electromaterials (anode, cathode and separator) are expected to sustain a deformation of 3% to 55% associated with body movement. Here, we report a stretchable fabric supercapacitor electrode using commonly available nylon lycra fabric as the substrate and graphene oxide (GO) as a dyestuff. It was prepared via a facile dyeing approach followed by a mild chemical reduction. This reduced graphene oxide (rGO) coated fabric electrode retains conductivity at an applied strain of up to …

Spin Fluctuations In The Exotic Metallic State Of Sr2ruo4 Studied With Β-Nmr, David L. Cortie, T Buck, M H. Dehn, R F. Kiefl, C D. P Levy, R M. L Mcfadden, G D. Morris, M R. Pearson, Z Salman, Y Maeno, W A. Macfarlane

Australian Institute for Innovative Materials - Papers

A β-NMR study was performed on a Sr2RuO4 crystal in the metallic state using a beam of spin-polarized 8Li+ implanted at a mean depth of 90 nm. The 8Li+ spin-lattice relaxation rate is strongly influenced by the onset of incommensurate spin fluctuations. The nuclear relaxation rate can be explained using previously published bulk 17O NMR and inelastic neutron spectroscopy measurements of the dynamic magnetic susceptibility to model the hyperfine coupling. A well-resolved quadrupolar-split NMR for 8Li+ implies a static stopping position in an interstitial site. The 8Li+ Knight shift is highly sensitive to the anisotropic static susceptibility.

Visualizing Superconductivity In Fese Nanoflakes On Srtio3 By Scanning Tunneling Microscopy, Zhi Li, Jun-Ping Peng, Hui-Min Zhang, Canli Song, Shuaihua Ji, Lili Wang, Ke He, Xiaowei Chen, Qi-Kun Xue, Xu-Cun Ma

Australian Institute for Innovative Materials - Papers

Scanning tunneling microscopy and spectroscopy have been employed to investigate the superconductivity in single unit-cell FeSe nanoflakes on SrTiO3 substrates. We find that the differential conductance dI/dV spectra are spatially nonuniform and fluctuate within the flakes as their area is reduced to below ∼150 nm2. An enhancement in the superconductivity-related gap size as large as 25% is observed. The superconductivity behavior disappears when the FeSe nanoflakes reduce to ∼40 nm2. Compared to a previous report [Wang et al., Chin. Phys. Lett. 29, 037402 (2012)], the gap is asymmetric relative to the Fermi energy EF. All the features, particularly the fluctuating …

Detection Of A Superconducting Phase In A Two-Atom Layer Of Hexagonal Ga Film Grown On Semiconducting Gan(0001), Hui-Min Zhang, Yi Sun, Wei Li, Jun-Ping Peng, Canli Song, Ying Xing, Qinghua Zhang, Jia-Qi Guan, Zhi Li, Yanfei Zhao, Shuaihua Ji, Lili Wang, Ke He, Xi Chen, Lin Gu, Langsheng Ling, Mingliang Tian, Lian Li, X. C Xie, Jianping Liu, Hui Yang, Qi-Kun Xue, Jian Wang, Xu-Cun Ma

Australian Institute for Innovative Materials - Papers

The recent observation of the superconducting state at atomic scale has motivated the pursuit of exotic condensed phases in two-dimensional (2D) systems. Here we report on a superconducting phase in twomonolayer crystalline Ga films epitaxially grown on wide-band-gap semiconductor GaN(0001). This phase exhibits a hexagonal structure and only 0.552 nm in thickness, nevertheless, brings about a superconducting transition temperature Tc as high as 5.4 K, confirmed by in situ scanning tunneling spectroscopy and ex situ electrical magnetotransport and magnetization measurements. The anisotropy of critical magnetic field and Berezinski-Kosterlitz-Thouless-like transition are observed, typical for the 2D superconductivity. Our results demonstrate a …

Origin Of The Enhanced Piezoelectric Thermal Stability In Bisco3-Pbtio3 Single Crystals, Lingping Kong, Gang Liu, Shujun Zhang, Wenge Yang

Australian Institute for Innovative Materials - Papers

BiScO 3 -PbTiO 3 single crystals were reported to possess high piezoelectric coefficient of 1200 pC/N and Curie temperature of > 400°C, exhibiting excellent thermal stability of properties up to 350°C. However, the origin of the thermal stability is yet unclear. In this research, high resolution synchrotron-based technique was used to study the temperature driven structural evolution in BiScO 3 -PbTiO 3 system, where two competing symmetries and local distortion were observed, accounting for the high piezoelectric activity. A strong correlation between thermal stability of structure and temperature-dependent properties was established, which will benefit the design of ferroelectric materials with broad …

Ambient Facile Synthesis Of Gram-Scale Copper Selenide Nanostructures From Commercial Copper And Selenium Powder, Xinqi Chen, Zhen Li, S X. Dou

Australian Institute for Innovative Materials - Papers

Grams of copper selenides (Cu_2-xSe) were prepared from commercial copper and selenium powders in the presence of thiol ligands by a one-pot reaction at room temperature. The resultant copper selenides are a mixture of nanoparticles and their assembled nanosheets, and the thickness of nanosheets assembled is strongly dependent on the ratio of thiol ligand to selenium powder. The resultant Cu_2-xSe (0 ≤ x ≤ 0.25) nanostructures were treated with hydrazine solution to remove the surface ligands and then explored as a potential thermoelectric candidate in comparison with commercial copper selenide powders. The research provides a novel …

Forum Proceedings From “Uavs: Pros Vs Cons Symposium” In Toronto, Canada, June 2013, Katina Michael

Associate Professor Katina Michael

Unmanned Aerial Systems (UAS), widely referred to as drones, are becoming increasingly relevant in civilian as well as military applications. UAS have been used by emergency services to help respond to and map environmental crises, to find missing people, to fight fires, and respond to traffic accidents. Their use in policing and border patrol functions is being trialled in many Western countries. Like other recent technologies (mobile phones etc), as they become cheaper and easier to use, they are likely to become much more prevalent in civilian life across a range of applications.

This conference will examine the current state …