Physical Sciences and Mathematics Commons^™

Two-Dimensional Nico2o4 Nanosheet-Coated Three-Dimensional Graphene Networks For High-Rate, Long-Cycle-Life Supercapacitors, Jiang Zhou, Ying Huang, Xiehong Cao, Bo Ouyang, Wenping Sun, Chaoliang Tan, Yu Zhang, Qinglang Ma, Shuquan Liang, Qingyu Yan, Hua Zhang

Australian Institute for Innovative Materials - Papers

We report the synthesis of two-dimensional (2D) NiCo2O4 nanosheet-coated three-dimensional graphene network (3DGN), which is then used as an electrode for high-rate, long-cycle-life supercapacitors. Using the 3DGN and nanoporous nanosheets, an ultrahigh specific capacitance (2173 F g^-1 at 6 A g^-1), excellent rate capability (954 F g^-1 at 200 A g^-1) and superior long-term cycling performance (94% capacitance retention after 14000 cycles at 100 A g^-1) are achieved.

Spatially-Confined Lithiation-Delithiation In Highly Dense Nanocomposite Anodes Towards Advanced Lithium-Ion Batteries, Yinzhu Jiang, Yong Li, Wenping Sun, Wei Huang, Jiabin Liu, Ben Xu, Chuanhong Jin, Tianyu Ma, Changzheng Wu, Mi Yan

Australian Institute for Innovative Materials - Papers

Spatially-confined electrochemical reactions are firstly realized in a highly dense nanocomposite anode for high performance lithium ion batteries. The spatially-confined lithiation-delithiation effectively avoids inter-cluster migration and perfectly retains full structural integrity. Large reversible capacity, high rate capability and superior cycling stability are achieved simultaneously. This spatially-confined lithiation-delithiation offers novel insight to enhance cycling performance of high capacity anode materials.

Surface Engineering And Design Strategy For Surface-Amorphized Tio 2 @Graphene Hybrids For High Power Li-Ion Battery Electrodes, Tengfei Zhou, Yang Zheng, Hong Gao, Shudi Min, Sean Li, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

Electrode materials with battery-like high capacity and capacitorlike rate performance are highly desirable, since they would signifi cantly advance next-generation energy storage technology. [ 1 ] TiO 2 has received increasing attention as an anode material for lithium-ion batteries (LIBs) due to its good reversible capacity and low volume expansion upon lithiation, as well as its low cost and safe lithiation potential. [ 2 ] The low lithium-ion mobility within the crystalline phase TiO 2 , however, together with its poor electrical conductivity, means that only a thin surface layer of the host material is available for Li intercalation at …

An Investigation Of The Nanomechanical Properties Of 0.5ba(Ti0.8zr0.2)O3-0.5(Ba0.7ca0.3)Tio3 Thin Films, Zhong-Lan Cai, Zeng-Mei Wang, Huan-Huan Wang, Zhenxiang Cheng, Baowen Li, Xin-Li Guo, Hideo Kimura, Akira Kasahara

Australian Institute for Innovative Materials - Papers

For practical application, the functional piezoelectric film in microelectromechanical systems should meet the requirement of physical properties, as well as the mechanical properties. In this article, 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 (0.5BZT-0.5BCT) thin films with varied properties were prepared on (100) Si substrates via a sol-gel technique at different annealing temperatures. The effects of the annealing temperature on the morphology, piezoelectricity, hardness, and elastic modulus were studied. Particular attention was paid to the surface frictional behavior of films, and the changes in the friction force can be radically explained in terms of differences in the hardness/elastic modulus ratio and the residual stress of films. …

Analysis Of Low-Field Isotropic Vortex Glass Containing Vortex Groups In Yba2cu3o7−X Thin Films Visualized By Scanning Squid Microscopy, Frederick Wells, Alexey V. Pan, Renshaw Wang, Sergey Fedoseev, Hans Hilgenkamp

Australian Institute for Innovative Materials - Papers

The glass-like vortex distribution in pulsed laser deposited YBa₂Cu₃O_{7 − x} thin films is observed by scanning superconducting quantum interference device microscopy and analysed for ordering after cooling in magnetic fields significantly smaller than the Earth's field. Autocorrelation calculations on this distribution show a weak short-range positional order, while Delaunay triangulation shows a near-complete lack of orientational order. The distribution of these vortices is finally characterised as an isotropic vortex glass. Abnormally closely spaced groups of vortices, which are statistically unlikely to occur, are observed above a threshold magnetic field. The origin of these groups …

Significantly Enhanced Critical Current Density In Nano-Mgb2 Grains Rapidly Formed At Low Temperature With Homogeneous Carbon Doping, Yongchang Liu, Feng Lan, Zongqing Ma, Ning Chen, Huijun Li, Shaon Barua, Dipakkumar Patel, Md S. Hossain, S Acar, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

High performance MgB₂ bulks using carbon-coated amorphous boron as a boron precursor were fabricated by Cu-activated sintering at low temperature (600 °C, below the Mg melting point). Dense nano-MgB₂ grains with a high level of homogeneous carbon doping were formed in these MgB₂ samples. This type of microstructure can provide a stronger flux pinning force, together with depressed volatility and oxidation of Mg owing to the low-temperature Cu-activated sintering, leading to a significant improvement of critical current density (J_c) in the as-prepared samples. In particular, the value of J_c for the carbon-coated (Mg …

Stimulus-Dependent Differences In Signalling Regulate Epithelial-Mesenchymal Plasticity And Change The Effects Of Drugs In Breast Cancer Cell Lines, Joseph Cursons, Karl-Johan Leuchowius, Mark Waltham, Eva Tomaskovic-Crook, Momeneh Foroutan, Cameron P. Bracken, Andrew Redfern, Edmund J. Crampin, Ian Street, Melissa J. Davis, Erik W. Thompson

Australian Institute for Innovative Materials - Papers

Introduction: The normal process of epithelial mesenchymal transition (EMT) is subverted by carcinoma cells to facilitate metastatic spread. Cancer cells rarely undergo a full conversion to the mesenchymal phenotype, and instead adopt positions along the epithelial-mesenchymal axis, a propensity we refer to as epithelial mesenchymal plasticity (EMP). EMP is associated with increased risk of metastasis in breast cancer and consequent poor prognosis. Drivers towards the mesenchymal state in malignant cells include growth factor stimulation or exposure to hypoxic conditions.

Methods: We have examined EMP in two cell line models of breast cancer: the PMC42 system (PMC42-ET and PMC42-LA …

3d-Bioprinting Of Cartilage For Orthopaedic Surgeons. Reading Between The Lines, Claudia Di Bella, Davide Donati, Amanda Fosang, Gordon G. Wallace, Peter F. M Choong

Australian Institute for Innovative Materials - Papers

Chondral and Osteochondral lesions represent one of the most challenging and frustrating scenarios for the orthopaedic surgeon and for the patient. The lack of therapeutic strategies capable to reconstitute the function and structure of hyaline cartilage and to halt the progression towards osteoarthritis has brought clinicians and scientists together, to investigate the potential role of tissue engineering as a viable alternative to current treatment modalities. In particular, the role of bioprinting is emerging as an innovative technology that allows for the creation of organized 3D tissue constructs via a "layer-by-layer" deposition process. This process also has the capability to combine …

3d Hierarchical Porous Graphene Aerogel With Tunable Meso-Pores On Graphene Nanosheets For High-Performance Energy Storage, Long Ren, K N. Hui, K S. Hui, Yundan Liu, Xiang Qi, Jianxin Zhong, Yi Du, Jianping Yang

Australian Institute for Innovative Materials - Papers

New and novel 3D hierarchical porous graphene aerogels (HPGA) with uniform and tunable mesopores (e.g., 21 and 53 nm) on graphene nanosheets (GNS) were prepared by a hydrothermal self-assembly process and an in-situ carbothermal reaction. The size and distribution of the meso-pores on the individual GNS were uniform and could be tuned by controlling the sizes of the Co3O4 NPs used in the hydrothermal reaction. This unique architecture of HPGA prevents the stacking of GNS and promises more electrochemically active sites that enhance the electrochemical storage level significantly. HPGA, as a lithium-ion battery anode, exhibited superior electrochemical performance, including a …

Injectable Phenytoin Loaded Polymeric Microspheres For The Control Of Temporal Lobe Epilepsy In Rats, Jonathan Jiang, Zhilian Yue, Sebastien Bauquier, Alan Lai, Yu Chen, Karen J. Mclean, Amy J. Halliday, Yi Sui, Simon E. Moulton, Gordon G. Wallace, Mark J. Cook

Australian Institute for Innovative Materials - Papers

Epilepsy is a prevalent neurological disorder with a high frequency of drug resistance. While significant advancements have been made in drug delivery systems to overcome anti-epileptic drug resistance, efficacies of materials in biological systems have been poorly studied. The purpose of the study was to evaluate the anti-epileptic effects of injectable poly(epsiloncaprolactone) (PCL) microspheres for controlled release of an anticonvulsant, phenytoin (PHT), in an animal model of epilepsy. Methods: PHT-PCL and Blank-PCL microspheres formulated using an oil-in-water (O/W) emulsion solvent evaporation method were evaluated for particle size, encapsulation efficiency, surface morphology and in-vitro drug release profile. Microspheres with the most …

Mass Acquisition Of Dirac Fermions In Magnetically Doped Topological Insulator Sb2te3 Films, Yeping Jiang, Canli Song, Zhi Li, Mu Chen, Richard L. Greene, Ke He, Lili Wang, Xiaowei Chen, Xu-Cun Ma, Qi-Kun Xue

Australian Institute for Innovative Materials - Papers

We report on the mass acquisition of Dirac fermions by doping Cr into the topmost quintuple layer or into the bulk of Sb2Te3 topological insulator films. By careful investigation of the scanning tunneling microscopy/spectroscopy on the films, we find that the Landau level spectrum keeps a good quality even at a high Cr-doping level, enabling a demonstration of deviation of the zeroth Landau level, induced by the acquisition of a mass term in the surface states in the presence of surface or bulk magnetic doping. The magnitude of the mass term in the surface states increases with increasing Cr-doping level. …

A Bio-Friendly, Green Route To Processable, Biocompatible Graphene/Polymer Composites, Eoin Murray, Sepidar Sayyar, Brianna C. Thompson, Robert A. Gorkin Iii, David L. Officer, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Grapene-based polymer composites are a very promising class of compounds for tissue engineering scaffolds. However, in general the methods of synthesis are environmentally hazardous and residual toxic materials can affect the biocompatibility significantly. In this paper a simple, scalable, environmentally-friendly, microwave-assisted synthesis is described that results in conducting graphene/polycaprolactone composites that retain the processability and biocompatibility of the pristine polymer without introducing possibly hazardous reducing agents. Composites of polycaprolactone and graphene oxide were synthesised in a single step by the ring-opening polymerisation of ε-caprolactone in the presence of dispersed graphene oxide nanosheets under microwave irradiation. The graphene oxide provides a …

Terahertz Probes Of Magnetic Field Induced Spin Reorientation In Yfeo 3 Single Crystal, Xian Lin, Junjie Jiang, Zuanming Jin, Dongyang Wang, Zhen Tian, Jiaguang Han, Zhenxiang Cheng, Guohong Ma

Australian Institute for Innovative Materials - Papers

Using the terahertz time-domain spectroscopy, we demonstrate the spin reorientation of a canted antiferromagnetic YFeO₃ single crystal, by evaluating the temperature and magnetic field dependence of resonant frequency and amplitude for the quasi-ferromagnetic (FM) and quasi-antiferromagnetic modes (AFM), a deeper insight into the dynamics of spin reorientation in rare-earth orthoferrites is established. Due to the absence of 4f-electrons in Y ion, the spin reorientation of Fe sublattices can only be induced by the applied magnetic field, rather than temperature. In agreement with the theoretical predication, the frequency of FM mode decreases with magnetic field. In addition, an …

Flexible Electrodes And Electrolytes For Energy Storage, Caiyun Wang, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The advent of flexible, wearable electronics has placed new demands on energy storage systems. The demands for high energy density achieved through the use of highly conducting materials with high surface area that enable facile electrochemical processes must now be coupled with the need for robustness and flexibility in each of the components: electrodes and electrolytes. This perspective provides an overview of materials and fabrication protocols used to produce flexible electrodes and electrolytes. We also discuss the key challenges in the development of high performance flexible energy storage devices. Only selected references are used to illustrate the myriad of developments …

Three-Dimensional Bio-Printing, Qi Gu, Jie Hao, Yangjie Lu, Liu Wang, Gordon G. Wallace, Qi Zhou

Australian Institute for Innovative Materials - Papers

Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at …

Modulation Of Photocatalytic Properties By Strain In 2d Biobr Nanosheets, Haifeng Feng, Zhongfei Xu, Liang Wang, Youxing Yu, David R. G Mitchell, Dandan Cui, Xun Xu, Ji Shi, Takumi Sannomiya, Yi Du, Weichang Hao, S X. Dou

Australian Institute for Innovative Materials - Papers

BiOBr nanosheets with highly reactive {001} facets exposed were selectively synthesized by a facile hydrothermal method. The inner strain in the BiOBr nanosheets has been tuned continuously by the pH value. The photocatalytic performance of BiOBr in dye degradation can be manipulated by the strain effect. The low-strain BiOBr nanosheets show improved photocatalytic activity. Density functional calculations suggest that strain can modify the band structure and symmetry in BiOBr. The enhanced photocatalytic activity in low-strain BiOBr nanosheets is due to improved charge separation attributable to a highly dispersive band structure with an indirect band gap.

Carbon Fibre Microelectrodes For Neuroscience Applications, Jian Fang, Zhigang Xie, Gordon G. Wallace, Xungai Wang

Australian Institute for Innovative Materials - Papers

Microelectrodes have shown outstanding performance in neural signal recording, neural stimulation and electrochemical sensing1,2. Compared with their micro-sized counterparts, microelectrodes normally exhibit improved signal-to-noise ratio, fast response time and can work with limited sample volumes. Microelectrodes are required to have good biocompatibility, low electrical impedance and long-term stability in many biomedical applications. Carbon fibres are manufactured from polymeric precursor fibres through carbonization, and high carbon content makes carbon fibres electrically conductive, corrosion resistant, biologically safe and inert3. Therefore, carbon fibre has been considered as an ideal candidate for making microelectrodes.

In this work, single carbon fibres were loaded into capillary …

Fish-Scale Bio-Inspired Multifunctional Zno Nanostructures, Ziqi Sun, Ting Liao, W Li, Yuhai Dou, Kesong Liu, Lei Jiang, Sang Woo Kim, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

Scales provide optical disguise, low water drag and mechanical protection to fish, enabling them to survive catastrophic environmental disasters, predators and microorganisms. The unique structures and stacking sequences of fish scales inspired the fabrication of artificial nanostructures with salient optical, interfacial and mechanical properties. Herein, we describe fish-scale bio-inspired multifunctional ZnO nanostructures that have similar morphology and structure to the cycloid scales of the Asian Arowana. These nanostructured coatings feature tunable light refraction and reflection, modulated surface wettability and damage-tolerant mechanical properties. The salient properties of these multifunctional nanostructures are promising for applications in (i) optical coatings, sensing or lens …

Synthesis Of Large And Few Atomic Layers Of Hexagonal Boron Nitride On Melted Copper, Majharu Haque Khan, Zhenguo Huang, Feng Xiao, Gilberto Casillas, Zhixin Chen, Paul Molino, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Hexagonal boron nitride nanosheets (h-BNNS) have been proposed as an ideal substrate for graphene-based electronic devices, but the synthesis of large and homogeneous h-BNNS is still challenging. In this contribution, we report a facile synthesis of few-layer h-BNNS on melted copper via an atmospheric pressure chemical vapor deposition process. Comparative studies confirm the advantage of using melted copper over solid copper as a catalyst substrate. The former leads to the formation of single crystalline h-BNNS that is several microns in size and mostly in mono- and bi-layer forms, in contrast to the polycrystalline and mixed multiple layers (1-10) yielded by …

Origin Of Resistivity Anomaly In P-Type Leads Chalcogenide Multiphase Compounds, Sima Aminorroaya-Yamini, David R. G Mitchell, Heng Wang, Zachary M. Gibbs, Yanzhong Pei, S X. Dou, G. Jeffrey Snyder

Australian Institute for Innovative Materials - Papers

The electrical resistivity curves for binary phase compounds of p-type lead chalcogenide (PbTe)_(0.9−x) (PbSe) _0.1 (PbS) _x, (x = 0.15, 0.2, 0.25), which contain PbS-rich secondary phases, show different behaviour on heating and cooling between 500-700 K. This is contrast to single phase compounds which exhibit similar behaviour on heating and cooling. We correlate these anomalies in the electrical resistivities of multiphase compounds to the variation in phase composition at high temperatures. The inhomogeneous distribution of dopants between the matrix and secondary phase is found to be crucial in the electronic transport properties of the multiphase compounds. …

Peptide Modification Of Purified Gellan Gum, Cameron Ferris, Leo Stevens, Kerry J. Gilmore, E Mume, Ivan Greguric, Damian Kirchmajer, Gordon G. Wallace, Marc In Het Panhuis

Australian Institute for Innovative Materials - Papers

Gellan gum (GG) is an anionic polysaccharide with potential as a biopolymer for additive manufacturing (3D-bioprinting) and tissue engineering. Previous studies have shown GG to be highly cytocompatible, but lacking specific attachment sites required for anchorage-dependent cells. In this work, we modify purified-GG polymer with a short peptide containing the arginine-glycine-aspartic acid (RGD) sequence that is known to enhance integrin-mediated cell attachment. Radiolabelling of the peptide was used in optimisation of the conjugation procedure to achieve an overall efficiency of 40%. The purification of divalent cations from commercial GG samples was found to be critical for successful conjugation. Rheological studies …

Nano-Carbon Electrodes For Thermal Energy Harvesting, Mark S. Romano, Joselito M. Razal, Dennis Antiohos, Gordon G. Wallace, Jun Chen

Australian Institute for Innovative Materials - Papers

Thermogalvanic cells are capable of converting waste heat (generated as a by-product of almost all human activity) to electricity. These devices may alleviate the problems associated with the use of fossil fuels to meet the world's current demand for energy. This review discusses the developments in thermogalvanic systems attained through the use of nano-carbons as the electrode materials. Advances in cell design and electrode configuration that improve performance of these thermo converters and make them applicable in a variety of environments are also summarized. It is the aim of this review to act as a channel for further developments in …

Hierarchically Porous Carbon-Zirconium Carbide Spheres As Potentially Reusable Transmutation Targets, Nicholas Scales, Jun Chen, Tracey L. Hanley, Daniel P. Riley, Gregory R. Lumpkin, Vittorio Luca

Australian Institute for Innovative Materials - Papers

The preparation of hierarchically porous phase-pure carbon-zirconium carbide spheres with surface areas upwards of 70 m²/g and diameters in the 1-2 mm range has been achieved. The zirconium carbide beads were prepared through carbothermal reduction of polyacrylonitrile-zirconium composites prepared via three different routes including infiltration of a zirconium precursor into preformed polyacrylonitrile (PAN) beads and two one-pot co-precipitation methods. Depending on the route used to prepare the composites, relatively high surface area phase-pure zirconium carbides with the radial macroporous internal structure of the PAN template could be prepared. The adsorption of the elements U, Mo, Cs and Sr …

Nano-Bioelectronics Via Dip-Pen Nanolithography, Cathal O'Connell, Michael J. Higgins, Simon E. Moulton, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The emerging field of nano-biology is borne from advances in our ability to control the structure of materials on finer and finer length-scales, coupled with an increased appreciation of the sensitivity of living cells to nanoscale topographical, chemical and mechanical cues. As we envisage and prototype nanostructured bioelectronic devices there is a crucial need to understand how cells feel and respond to nanoscale materials, particularly as material properties (surface energy, conductivity etc.) can be very different at the nanoscale than at the bulk. However, the patterning of organic bioelectronic materials is often not achievable using conventional fabrication techniques, especially on …

Semimetal-Semiconductor Transition And Giant Linear Magnetoresistances In Three-Dimensional Dirac Semimetal Bi0.96sb0.04 Single Crystals, Zengji Yue, Xiaolin Wang, Shi-Shen Yan

Australian Institute for Innovative Materials - Papers

Three-dimensional (3D) Dirac semimetals are new quantum materials and can be viewed as 3D analogues of graphene. Many fascinating electronic properties have been proposed and realized in 3D Dirac semimetals, which demonstrate their potential applications in next generation quantum devices. Bismuth-antimony Bi1− x Sb x can be tuned from a topological insulator to a band insulator through a quantum critical point at x ≈ 4%, where 3D Dirac fermions appear. Here, we report on a magnetotransport study of Bi1− x Sb x at such a quantum critical point. An unusual magnetic-field induced semimetal-semiconductor phase transition was observed in the Bi0.96Sb0.04 …

The Effect Of Symmetry On Resonant And Nonresonant Photoresponses In A Field-Effect Terahertz Detector, J D. Sun, H Qin, Roger A. Lewis, Xiaoyu Yang, Y F. Sun, Zhenpu Zhang, Xianghu Li, Xiaoqin Zhang, Y Cai, D M. Wu, B S. Zhang

Australian Institute for Innovative Materials - Papers

The effect of the symmetries in the terahertz (THz) field distribution and the field-effect channel on THz photoresponse is examined. Resonant excitation of cavity plasmon modes and nonresonant self-mixing of THz waves are demonstrated in a GaN/AlGaN two-dimensional electron gas with symmetrically designed nanogates, antennas, and filters. We found that the self-mixing signal can be effectively suppressed by the symmetric design and the resonant response benefits from the residual asymmetry. The findings suggest that a single detector may provide both high sensitivity from the self-mixing mechanism and spectral resolution from the resonant response by optimizing the degree of geometrical and/or …

Hollow Carbon Spheres With Encapsulated Germanium As An Anode Material For Lithium Ion Batteries, Dan Li, Chuanqi Feng, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel composite consisting of hollow carbon spheres with encapsulated germanium (Ge@HCS) was synthesized by introducing a germanium precursor into the porous-structured hollow carbon spheres. The carbon spheres not only function as a scaffold to hold the germanium and thus maintain the structural integrity of the composite, but also increase the electrical conductivity. The voids and vacancies that are formed after the reduction of germanium dioxide to germanium provide free space for accommodating the volume changes during discharging-charging processes, thus preventing pulverization. The obtained Ge@HCS composite exhibits excellent lithium storage performance, as revealed by electrochemical evaluation.

Aqueous Preparation Of Surfactant-Free Copper Selenide Nanowires, Xinqi Chen, Zhen Li, Jianping Yang, Qiao Sun, S X. Dou

Australian Institute for Innovative Materials - Papers

Uniform surfactant-free copper selenide (Cu_{2- x} Se) nanowires were prepared via an aqueous route. The effects of reaction parameters such as Cu/Se precursor ratio, Se/NaOH ratio, and reaction time on the formation of nanowires were comprehensively investigated. The results show that Cu_{2- x} Se nanowires were formed through the assembling of CuSe nanoplates, accompanied by their self-redox reactions. The resultant Cu_{2- x} Se nanowires were explored as a potential thermoelectric candidate in comparison with commercial copper selenide powder. Both synthetic and commercial samples have a similar performance and their figures of merit are 0.29 and 0.38 at …

One-Pot Synthesis Of Ultra-Small Magnetite Nanoparticles On The Surface Of Reduced Graphene Oxide Nanosheets As Anodes For Sodium-Ion Batteries, Shaohua Zhang, Weijie Li, Bien Tan, Shulei Chou, Zhen Li, S X. Dou

Australian Institute for Innovative Materials - Papers

Nanocomposites with ultra-small magnetite (Fe₃O₄) nanoparticles (approx. 3 nm) uniformly anchored on the surfaces of reduced graphene oxide (RGO) nanosheets were successfully synthesized for anodes in sodium-ion batteries by a novel single-step high-temperature coprecipitation approach. The best electrode delivers a reversible Na⁺ storage capacity of 204 mA h g^-1 with excellent capacity retention, i.e., 98% of the second-cycle value was retained after 200 cycles.

Mgb2 Superconducting Joints For Persistent Current Operation, Dipakkumar Patel, Md S. Hossain, Khay Wai W. See, Xun Xu, Shaon Barua, Zongqing Ma, Seyong Choi, Mike Tomsic, Jung Ho Kim

Australian Institute for Innovative Materials - Papers

High-performance superconducting joints are essential for realizing persistent-mode magnets. Herein, we propose a concept and fabrication of such superconducting joints, which yielded reliable performance in the operating temperature range of 4.2-25 K. MgB₂-MgB₂ joints in magnets are known to result in deterioration of localized electrical, thermal, and mechanical properties. To overcome these problems, the ends of the two wires are inserted into a pellet press, which is then filled with a mixture of unreacted magnesium and boron powders, followed by heat treatment. The critical current capacity and joint resistance were precisely evaluated by the standard four-probe method …