Physical Sciences and Mathematics Commons^™

A Study On The Charge-Discharge Mechanism Of Co3o4 As An Anode For The Li Ion Secondary Battery, Yong-Mook Kang, Min-Sang Song, Jin-Ho Kim, Hyun-Seok Kim, Min-Sik Park, Jai-Young Lee, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Co₃O₄ has shown acceptable electrochemical properties as the anode material of Li secondary batteries. In detail, its capacity reached about 700 mAh/g, twice as high as graphite, and 93.4% of initial capacity was retained after 100 cycles. EIS (electrochemical impedance spectroscopy) analyses revealed that after the 1st cycle, the insertion or extraction of Li ions in Co₃O₄ can occur homogeneously and reversibly (randless-like behavior, homogeneous mixture: Co + Li₂O (in the state of Li insertion), Co₃O₄ (in the state of Li extraction)). In fact, the coulombic efficiency of Co …

A New Magnetoplasmon Sound Wave In A Two-Dimensional Electron Gas Under Electromagnetic Radiation, C Zhang, S Hessami Pilehrood

Australian Institute for Innovative Materials - Papers

We report a new magnetoplasmon mode and a sound-like collective excitation in two-dimensional electronic systems under a weak magnetic field and a low-frequency electromagnetic radiation. The analysis is based on the exact time-dependent wave functions and the exact relation between response function with and without radiation. The new mode discovered here can be used as a generating mechanism of high-frequency radiation from a system whose characteristic energy is low.

Magnetic And Transport Properties Of The Layered Perovskite System Sr2-Yyycoo4 (0< Y < 1), Xiaolin Wang, E Takayama-Muromachi

Australian Institute for Innovative Materials - Papers

Layered perovskite cobalt oxides Sr2-yYyCoO4 (y=0, 0.1, 0.3, 0.5, 0.67, 0.83 and 1) were synthesized under high pressure and high temperature conditions.

Nonmagnetic Insulator State In Na1coo2 And Phase Separation Of Na Vacancies, C De Vaulx, M. -H Julien, C Berthier, M Horvatic, P Bordet, V Simonet, Dapeng Chen, C T. Lin

Australian Institute for Innovative Materials - Papers

Crystallographic, magnetic, and NMR properties of a NaxCoO2 single crystal with x≃1 are presented. We identify the stoichiometric Na1CoO2 phase, which is shown to be a nonmagnetic insulator, as expected for homogeneous planes of Co3+ ions with S=0. In addition, we present evidence that, because of slight average Na deficiency, chemical and electronic phase separation leads to a segregation of Na vacancies into the well-defined, magnetic, Na0.8CoO2 phase. The importance of phase separation is discussed in the context of magnetic order for x≃0.8 and the occurrence of a metal-insulator transition for x→1.

1-(4-Chlorophenyl)-2-Methyl-4-Nitro-5-(1-Piperidyl)-1h-Imidazole, Maciej Kubicki, Pawel Wagner

Australian Institute for Innovative Materials - Papers

The only specific interactions that influence the crystal packing of the title compound, C15H17ClN4O2, are weak C-H...N and C-H...Cl hydrogen bonds, even though there is a possibility of, for example, pi-pi stacking or halogen bonding. The dihedral angle between the mean planes of the imidazole and benzene rings is 59.82 (5) degrees . The length of the C-N bond connecting the imidazole and piperidine fragments is correlated with the degree of pyramidalization of the piperidine N atom.

Ybco Coated Conductor Using Biaxially Textured Clad Composite Ni-Mn/Ni-Cr Substrate, D Q. Shi, S X. Dou, R. K. Ko, J K. Chung, H S. Kim, H S. Ha, K J. Song, C. Park

Australian Institute for Innovative Materials - Papers

A new biaxially textured composite tape of Ni–4.5% Mn/Ni–1.5% Cr was used as a substrate for a YBCO coated conductor through the RABiTS approach. Multi-layer CeO₂/YSZ/Y₂O₃ buffer layers and YBCO film were deposited on the substrate by pulsed laser deposition. The deposition conditions of the buffer layers and the YBCO were studied and compared. Good biaxial textures have been obtained for buffer layers on composite Ni–4.5% Mn/Ni–1.5% Cr substrates. Scanning electron microscopy on sample cross-sections was used to examine the interface and diffusion of oxygen. The uniform formation of an Ni–Mn–O layer between NiO and …

Atomic Layer Depostion Of Tio2/Al2o3 Films For Optical Applications, G Triani, P J. Evans, D Rg Mitchell, D J. Attard, K Finnie, M James, T Hanley, B Latella, Kathryn Prince, J Bartlett

Australian Institute for Innovative Materials - Papers

Atomic layer deposition (ALD) is an important technology for depositing functional coatings on accessible, reactive surfaces with precise control of thickness and nanostructure. Unlike conventional chemical vapour deposition, where growth rate is dependent on reactant flux, ALD employs sequential surface chemical reactions to saturate a surface with a (sub-) monolayer of reactive compounds such as metal alkoxides or covalent halides, followed by reaction with a second compound such as water to deposit coatings layer-by-layer. A judicious choice of reactants and processing conditions ensures that the reactions are self-limiting, resulting in controlled film growth with excellent conformality to the substrate.

This …

Double Injection As A Technique To Study Charge Carrier Transport And Recombination In Bulk-Heterojunction Solar-Cells, G Juska, K Arlauskas, G Sliauzys, A Pivrikas, Attila Mozer, Serdar Sariciftci, Markus Scharber, R Osterbacka

Australian Institute for Innovative Materials - Papers

Ambipolar charge carriermobility and recombination in bulk-heterojunction solar cells based on the mixture of regioregular poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene (PCBM) has been studied using injection current transients. The experimental results demonstrate double injection with bimolecular recombination limiting the injection current. We found that charge carrier bimolecular recombination is significantly reduced compared to Langevin recombination. We have measured the temperature and electric field dependence of the reduced bimolecular recombination coefficient and the results suggest that the electron and hole pathways are different and the recombination is controlled by the probability of the carriers to meet at the polymer/PCBM interface.

Charge Transport And Recombination In Bulk Heterojunction Solar Cells Studied By The Photoinducted Charge Extraction By Linearly Increasing Voltage Technique, Attila Mozer, Serdar Sariciftci, Laurence Lutsen, Dirk Vanderzande, R Osterbacka, M Westerling, G Juska

Australian Institute for Innovative Materials - Papers

Charge carriermobility and recombination in a bulk heterojunctionsolar cell based on the mixture of poly[2-methoxy-5-(3,7-dimethyloctyloxy)-phenylene vinylene] (MDMO-PPV) and 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)-C₆₁ (PCBM) has been studied using the novel technique of photoinduced charge carrier extraction in a linearly increasing voltage (Photo-CELIV). In this technique, charge carriers are photogenerated by a short laser flash, and extracted under a reverse bias voltage ramp after an adjustable delay time (t_del). The Photo-CELIV mobility at room temperature is found to be μ = 2 × 10⁻⁴ cm² V⁻¹ s⁻¹, which is almost independent on charge carrier density, but slightly …

Magnetic Ordering And Spin Waves In Na0.82coo2, S P. Bayrakci, I Mirebeau, P Bourges, Y Sidis, M Enderle, J Mesot, Dapeng Chen, C T Lin, B Keimer

Australian Institute for Innovative Materials - Papers

NaxCoO2, the parent compound of the recently synthesized superconductor NaxCoO2∶yH2O, exhibits bulk antiferromagnetic order below ∼20   K for 0.75≤x≤0.9. We have performed neutron scattering experiments in which we observed Bragg reflections corresponding to A-type antiferromagnetic order in a Na0.82CoO2 single crystal and characterized the corresponding spin-wave dispersions. The spin waves exhibit a strongly energy-dependent linewidth. The in-plane and out-of-plane exchange constants resulting from a fit to a nearest-neighbor Heisenberg model are similar in magnitude, which is unexpected in view of the layered crystal structure of NaxCoO2. Possible implications of these observations are discussed.

Off-Axis Mgb2 Films Using An In Situ Annealing Pulsed Laser Deposition Method, Yue Zhao, Mihail Ionescu, Josip Horvat, S X. Dou

Australian Institute for Innovative Materials - Papers

Highly smooth and c-axis oriented superconducting MgB₂ thin films were prepared by pulsed laser deposition (PLD) with off-axis geometry. The films were deposited on Al₂O₃–C substrates perpendicularly aligned to a stoichiometric MgB₂ target in a 120 mTorr high purity Ar background gas. An in situ annealing was carried out at 650 °C for 1 min in a 760 Torr Ar atmosphere. Despite the short annealing time, an x-ray θ–2θ scan shows fairly good crystallization, according to the clear c-axis oriented peaks for the films. Both atomic force microscopy and the x-ray diffraction …

Effect Of Doping On Flux Pinning Of Gdba2cu3o7-Y, L Zhang, X B Xu, S Y Ding, M H Zheng, L Xiao, H T Ren, Y L Jiao, Xiaolin Wang, Zhi W. Lin, Jian G. Zhu

Australian Institute for Innovative Materials - Papers

Cylindrical single grains of GdBa 2Cu3Oy sGd-123d with a diameter of 25 mm were successfully fabricated by melt-texture growth sMTGd process in air to study the influence of different starting powders on flux pinning. Measurements of the magnetic critical current density sJcd showed that it was possible to fabricate large Gd-123 single grain with a high Jc at high temperatures and fields by means of properly controlling the starting powders of Gd 2O3, BaCO3 , and CuO before the process.

Nano-Structured Sno2-Carbon Composites Obtained By In Situ Spray Pyrolysis Method As Anodes In Lithium Batteries, Ling Yuan, Konstantin Konstantinov, Guoxiu Wang, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

In this paper, we report on a series of SnO₂-carbon nano-composites synthesized by in situ spray pyrolysis of a solution of SnCl₂·2H₂O and sucrose at 700 °C. The process results in super fine nanocrystalline SnO₂, which is homogeneously distributed inside the amorphous carbon matrix. The SnO₂ was revealed as a structure of broken hollow spheres with porosity on both the inside and outside particle surfaces. This structure promises a highly developed specific surface area. X-ray diffraction (XRD) patterns and transmission electron microscope (TEM) images revealed the SnO₂ crystal size is …