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Full-Text Articles in Physical Sciences and Mathematics

Tuneable Magnetic Phase Transitions In Layered Cemn2ge2-Xsix Compounds, M F. Md Din, Jianli Wang, Zhenxiang Cheng, S X. Dou, Shane J. Kennedy, Maxim Avdeev, Stewart J. Campbell Jan 2015

Tuneable Magnetic Phase Transitions In Layered Cemn2ge2-Xsix Compounds, M F. Md Din, Jianli Wang, Zhenxiang Cheng, S X. Dou, Shane J. Kennedy, Maxim Avdeev, Stewart J. Campbell

Australian Institute for Innovative Materials - Papers

The structural and magnetic properties of seven CeMn2Ge2-xSix compounds with x = 0.0-2.0 have been investigated in detail. Substitution of Ge with Si leads to a monotonic decrease of both a and c along with concomitant contraction of the unit cell volume and significant modifications of the magnetic states - a crossover from ferromagnetism at room temperature for Ge-rich compounds to antiferromagnetism for Si-rich compounds. The magnetic phase diagram has been constructed over the full range of CeMn2Ge2-xSix compositions and co-existence of ferromagnetism and antiferromagnetism has been observed in CeMn …


Fabrication Of Thermoelectric Materials-Thermal Stability And Repeatability Of Achieved Efficiencies, Sima Aminorroaya-Yamini, Matthew D. Brewis, Jacob Byrnes, Rafael Santos, Andrew Manettas, Y Z. Pei Jan 2015

Fabrication Of Thermoelectric Materials-Thermal Stability And Repeatability Of Achieved Efficiencies, Sima Aminorroaya-Yamini, Matthew D. Brewis, Jacob Byrnes, Rafael Santos, Andrew Manettas, Y Z. Pei

Australian Institute for Innovative Materials - Papers

Metal chalcogenides have delivered the highest efficiencies among thermoelectric materials. Although the thermal stability of thermoelectric materials at device operating temperatures has been of concern, recent studies have reported the efficiencies of materials prepared with different fabrication techniques. Here, we have fabricated a p-type, multiphase lead chalcogenide compound of (PbTe)0.55(PbS)0.35(PbSe)0.1, with three common fabrication techniques of quenched, quenched-annealed and furnace cooled followed by spark plasma sintering. The compound contains PbS-rich precipitates within a PbTe-rich matrix. The achieved samples from various fabrication procedures demonstrate distinct microstructures that evolve with thermal cycling. We have shown that the thermoelectric efficiency of metastable compound …


3d Braided Yarns To Create Electrochemical Cells, Chen Zhao, Syamak Farajikhah, Caiyun Wang, Javad Foroughi, Xiaoteng Jia, Gordon G. Wallace Jan 2015

3d Braided Yarns To Create Electrochemical Cells, Chen Zhao, Syamak Farajikhah, Caiyun Wang, Javad Foroughi, Xiaoteng Jia, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

The demands for new configurations of electrochemical cells continue to grow and novel approaches are being enabled by the advent of new electromaterials and novel fabrication strategies. Wearable energy storage devices that can be seamlessly integrated into garments are a critical component of the wearable electronics genre. Recently, flexible yarn supercapacitors have attracted significant attention due to their ability to be integrated into fabrics, or stitched into existing textiles. Large-scale production of yarn supercapacitors using conventional manufacturing processes, however, is still a challenge. Here, we introduce the use of braiding technology to achieve a predetermined arrangement of fibre electrodes, the …


Three-Dimensional Controlled Growth Of Monodisperse Sub-50 Nm Heterogeneous Nanocrystals, Deming Liu, Xiaoxue Xu, Yi Du, Xian Qin, Yuhai Zhang, Chenshuo Ma, Shihui Wen, Wei Ren, Ewa M. Goldys, James A. Piper, S X. Dou, Xiaogang Liu, Dayong Jin Jan 2015

Three-Dimensional Controlled Growth Of Monodisperse Sub-50 Nm Heterogeneous Nanocrystals, Deming Liu, Xiaoxue Xu, Yi Du, Xian Qin, Yuhai Zhang, Chenshuo Ma, Shihui Wen, Wei Ren, Ewa M. Goldys, James A. Piper, S X. Dou, Xiaogang Liu, Dayong Jin

Australian Institute for Innovative Materials - Papers

The ultimate frontier in nanomaterials engineering is to realize their composition control with atomic scale precision to enable fabrication of nanoparticles with desirable size, shape and surface properties. Such control becomes even more useful when growing hybrid nanocrystals designed to integrate multiple functionalities. Here we report achieving such degree of control in a family of rare-earth-doped nanomaterials. We experimentally verify the co-existence and different roles of oleate anions (OA-) and molecules (OAH) in the crystal formation. We identify that the control over the ratio of OA- to OAH can be used to directionally inhibit, promote or etch the crystallographic facets …


Conductive Surfaces With Dynamic Switching In Response To Temperature And Salt, Alissa Hackett, Jenny Malmström, Paul J. Molino, Julien Gautrot, Hongrui Zhang, Michael J. Higgins, Gordon G. Wallace, David E. Williams, Jadranka Travas-Sejdic Jan 2015

Conductive Surfaces With Dynamic Switching In Response To Temperature And Salt, Alissa Hackett, Jenny Malmström, Paul J. Molino, Julien Gautrot, Hongrui Zhang, Michael J. Higgins, Gordon G. Wallace, David E. Williams, Jadranka Travas-Sejdic

Australian Institute for Innovative Materials - Papers

This work demonstrates polymer brushes grafted from conductive polymer films which display dynamic surface switching dependent on salt, temperature and electrode potential. The electroactivity presented by the conductive polymer and the responsiveness of the grafted brushes leads to an interface with multiple control parameters. Here, we demonstrate this concept by grafting of uncharged brushes of poly(ethylene glycol)methyl ether methacrylates from conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), and observe a temperature- and salt-induced switch of brush conformation, and their effect on the electrochemistry of the material. The switching conditions can be tailored by copolymerizing monomers with different numbers of ethylene glycol units. In …


Hierarchical Heteroaggregation Of Binary Metal-Organic Gels With Tunable Porosity And Mixed Valence Metal Sites For Removal Of Dyes In Water, Asif Mahmood, Wei Xia, Nasir Mahmood, Qingfei Wang, Ruqiang Zou Jan 2015

Hierarchical Heteroaggregation Of Binary Metal-Organic Gels With Tunable Porosity And Mixed Valence Metal Sites For Removal Of Dyes In Water, Asif Mahmood, Wei Xia, Nasir Mahmood, Qingfei Wang, Ruqiang Zou

Australian Institute for Innovative Materials - Papers

Hierarchical heteronuclear metal-organic gels (MOGs) based on iron (Fe) and aluminium (Al) metal-organic framework (MOF) backbones bridged by tri-carboxylate ligands have firstly been synthesized by simple solvothermal method. Monometallic MOGs based on Fe or Al give homogenous monoliths, which have been tuned by introduction of heterogeneity in the system (mismatched growth). The developed gels demonstrate that surface areas, pore volumes and pore sizes can be readily tuned by optimizing heterogeneity. The work also elaborates effect of heterogeneity on size of MOG particles which increase substantially with increasing heterogeneity as well as obtaining mixed valence sites in the gels. High surface …


Trap-Assisted Transport And Non-Uniform Charge Distribution In Sulphur-Rich Pbs Colloidal Quantum Dot-Based Solar Cells With Selective Contacts, Victor Malgras, Guanran Zhang, Andrew Nattestad, Tracey M. Clarke, Attila J. Mozer, Yusuke Yamauchi, Jung Ho Kim Jan 2015

Trap-Assisted Transport And Non-Uniform Charge Distribution In Sulphur-Rich Pbs Colloidal Quantum Dot-Based Solar Cells With Selective Contacts, Victor Malgras, Guanran Zhang, Andrew Nattestad, Tracey M. Clarke, Attila J. Mozer, Yusuke Yamauchi, Jung Ho Kim

Australian Institute for Innovative Materials - Papers

This study reports evidences of dispersive transport in planar PbS colloidal quantum dots heterojunction-based devices as well as the effect of incorporating a MoO3 hole selective layer on the charge extraction behavior. Steady state and transient characterization techniques are employed to determine the complex recombination processes involved in such devices. The addition of a selective contact drastically improves the device efficiency up to 3.15 % (especially through the photocurrent and series resistance) and extends the overall charge lifetime by suppressing the main first-order recombination pathway observed in device without MoO3. The lifetime and mobility calculated for our sulphur-rich PbS-based devices …


Research Progress On Design Strategies, Synthesis And Performance Of Limn2o4-Based Cathodes, Fangxin Mao, Wei Dong Guo, Jianmin Ma Jan 2015

Research Progress On Design Strategies, Synthesis And Performance Of Limn2o4-Based Cathodes, Fangxin Mao, Wei Dong Guo, Jianmin Ma

Australian Institute for Innovative Materials - Papers

Spinel LiMn2O4 (LMO)-based composites, due to their combination of low toxicity, abundant natural resources, and excellent electrochemical performance, are regarded as promising candidate cathode materials for lithium ion batteries. Current energy storage demands are not being met with existing materials, however, because of their defects, such as fast capacity fading, low rate capability, and low specific capacity in practical applications. Manganese dissolution during electrochemical processes bears the major responsibility for capacity loss, apart from the electrolyte factor. Low electrical conductivity, low ionic diffusion efficiency, and large structural variation have adverse effects on the electrochemical performance of materials. With respect to …


Vanadium-Based Nanostructure Materials For Secondary Lithium Battery Applications, Hui Teng Tan, Xianhong Rui, Wenping Sun, Qingyu Yan, Tuti M. Lim Jan 2015

Vanadium-Based Nanostructure Materials For Secondary Lithium Battery Applications, Hui Teng Tan, Xianhong Rui, Wenping Sun, Qingyu Yan, Tuti M. Lim

Australian Institute for Innovative Materials - Papers

Vanadium-based materials, such as V2O5, LiV3O8, VO2(B) and Li3V2(PO4)3 are compounds that share the characteristic of intercalation chemistry. Their layered or open frameworks allow facile ion movement through the interspaces, making them promising cathodes for LIB applications. To bypass bottlenecks occurring in the electrochemical performances of vanadium-based cathodes that derive from their intrinsic low electrical conductivity and ion diffusion coefficients, nano-engineering strategies have been implemented to "create" newly emerging properties that are unattainable at the bulk solid level. Integrating this concept into vanadium-based cathodes represents a promising way to circumvent the aforementioned problems as nanostructuring offers potential improvements in electrochemical …


Coherent And Tunable Terahertz Radiation From Graphene Surface Plasmon Polarirons Excited By Cyclotron Electron Beam, Tao Zhao, Sen Gong, Min Hu, Renbin Zhong, Diwei Liu, Xiaoxing Chen, Ping Zhang, Xinran Wang, C Zhang, Peiheng Wu, Shenggang Liu Jan 2015

Coherent And Tunable Terahertz Radiation From Graphene Surface Plasmon Polarirons Excited By Cyclotron Electron Beam, Tao Zhao, Sen Gong, Min Hu, Renbin Zhong, Diwei Liu, Xiaoxing Chen, Ping Zhang, Xinran Wang, C Zhang, Peiheng Wu, Shenggang Liu

Australian Institute for Innovative Materials - Papers

Terahertz (THz) radiation can revolutionize modern science and technology. To this date, it remains big challenges to develop intense, coherent and tunable THz radiation sources that can cover the whole THz frequency region either by means of only electronics (both vacuum electronics and semiconductor electronics) or of only photonics (lasers, for example, quantum cascade laser). Here we present a mechanism which can overcome these difficulties in THz radiation generation. Due to the natural periodicity of 2π of both the circular cylindrical graphene structure and cyclotron electron beam (CEB), the surface plasmon polaritions (SPPs) dispersion can cross the light line of …