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Articles 1 - 7 of 7

Full-Text Articles in Engineering

Graphene V2o5 Nh2o Xerogel Composite Cathodes For Lithium Ion Batteries, Guodong Du, Kuok Hau Seng, Zaiping Guo, Jun Liu, Wenxian Li, D Z. Jia, Christopher D. Cook, Z Liu, Hua-Kun Liu Jan 2011

Graphene V2o5 Nh2o Xerogel Composite Cathodes For Lithium Ion Batteries, Guodong Du, Kuok Hau Seng, Zaiping Guo, Jun Liu, Wenxian Li, D Z. Jia, Christopher D. Cook, Z Liu, Hua-Kun Liu

Faculty of Engineering - Papers (Archive)

A layer structured V2O5·nH2O xerogel was synthesized via a simple green hydrothermal technique by dissolving commercial V2O5 powder in de-ionized water and hydrogen peroxide. Graphene–V2O5·nH2O xerogel composites were then prepared by mixing and filtration of as-prepared V2O5·nH2O xerogel and graphene in the desired ratio. The method is a cost effective and energy saving way to prepare nanostructured composites. Structure and morphology were investigated by X-ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, …


Nonlinear Transverse Current Response In Zigzag Graphene Nanoribbons, Bo Wang, Zhongshui Ma, Chao Zhang Jan 2011

Nonlinear Transverse Current Response In Zigzag Graphene Nanoribbons, Bo Wang, Zhongshui Ma, Chao Zhang

Faculty of Engineering - Papers (Archive)

By employing a self-consistent approach, we reveal a number of unique properties of zigzag graphene nanoribbons under crossed electric and magnetic fields: (1) a very strong electrical polarization along the transverse direction of the ribbon, and (2) a strong nonlinear Hall current under a rather moderate electrical field. At the field strength of 5000 V/cm, the ratio of the nonlinear current to the linear current is around 1 under an applied magnetic field of 7.9 T. Our results suggest that graphene nanoribbons are an ideal system to achieve a large electrical polarizability. Our results also suggest that the nonlinear effect …


Transverse Current Response In Armchair Graphene Ribbons, Junfeng Liu, Zhongshui Ma, Chao Zhang Jan 2011

Transverse Current Response In Armchair Graphene Ribbons, Junfeng Liu, Zhongshui Ma, Chao Zhang

Faculty of Engineering - Papers (Archive)

We demonstrate that the direction of transverse current in graphene nanoribbons under a magnetic field can be tuned with a gate voltage. It is shown that for armchair ribbons there exist extra energy regions where the direction of the Hall current can be switched between positive and negative values. The directional change of the Hall current coincides with the special points where the two lowest energy bands in the spectrum become degenerate (band crossing points). The number of such degenerate points depends on the width of the ribbons. The dependence of the sign reversal on the gate voltage provides a …


Superconducting Properties Of Graphene Doped Magnesium Diboride, Xun Xu, Wenxian Li, Xiaolin Wang, S. X. Dou Jan 2011

Superconducting Properties Of Graphene Doped Magnesium Diboride, Xun Xu, Wenxian Li, Xiaolin Wang, S. X. Dou

Faculty of Engineering - Papers (Archive)

Graphene, carbon in the form of monolayer sheets, has revealed astonishing and unique chemical and physical properties, which have made it an extremely active research topic in both materials science and physics (Novoselov, K. S. et al., 2004). Through chemical and materials integration, graphene is being actively exploited in a range of technological applications (Stankovich, S. et al., 2006). Superconductors can carry electrical current without any energy dissipation. The combination of both graphene and a superconductor into a composite has great potential for electrical devices and large scale applications. MgB2, a superconductor with a simple composition and two-gap feature has …


Two-Color Terahertz Response In Bilayer Graphene Nanoribbons With Spin-Orbit Coupling, Junfeng Liu, Bo Wang, Zhongshui Ma, Chao Zhang Jan 2011

Two-Color Terahertz Response In Bilayer Graphene Nanoribbons With Spin-Orbit Coupling, Junfeng Liu, Bo Wang, Zhongshui Ma, Chao Zhang

Faculty of Engineering - Papers (Archive)

We demonstrate that spin-orbit coupling can give rise to a strong terahertz response in metallic armchair bilayer graphene nanoribbons. The combination of the interlayer coupling and the spin-orbit coupling leads to double resonant optical response in the low frequency regime. The frequency separation of the two excitations is tunable with a gate voltage.


Energy-Loss Rate Of A Fast Particle In Graphene, Yee Sin Ang, Chao Zhang, Chun Kee Jan 2011

Energy-Loss Rate Of A Fast Particle In Graphene, Yee Sin Ang, Chao Zhang, Chun Kee

Faculty of Engineering - Papers (Archive)

The energy-loss rate of a fast particle in graphene is studied. The energy-loss rate always increases with increasing incident particle energy, which is quite unusual when compared to electron gas in normal metal. Graphene exhibits a “discriminating” behavior where there exists a low energy cut-off below which the scattering process is strictly forbidden, leading to lossless traverse of an external particle in graphene. This low energy cutoff is of the order of nearest neighbor hopping bandwidth. Our results suggest that backscattering is also absent in the external particle scattering of graphene.


Molecular-Beam Epitaxy And Robust Superconductivity Of Stoichiometric Fese Crystalline Films On Bilayer Graphene, Canli Song, Yi-Lin Wang, Yeping Jiang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue Jan 2011

Molecular-Beam Epitaxy And Robust Superconductivity Of Stoichiometric Fese Crystalline Films On Bilayer Graphene, Canli Song, Yi-Lin Wang, Yeping Jiang, Zhi Li, Lili Wang, Ke He, Xi Chen, Xu-Cun Ma, Qi-Kun Xue

Australian Institute for Innovative Materials - Papers

We report on molecular beam epitaxy growth of stoichiometric and superconducting FeSe crystalline thin films on double-layer graphene. Layer-by-layer growth of high-quality films has been achieved in a well-controlled manner by using Se-rich condition, which allow us to investigate the thickness-dependent superconductivity of FeSe. In situ low-temperature scanning tunneling spectra reveal that the local superconducting gap in the quasiparticle density of states is visible down to two triple layers for the minimum measurement temperature of 2.2 K, and that the transition temperature Tc scales inversely with film thickness.