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Thermionic Cooling In Cylindrical Semiconductor Nanostructures, Pin Lyu, Chao Zhang
Thermionic Cooling In Cylindrical Semiconductor Nanostructures, Pin Lyu, Chao Zhang
Australian Institute for Innovative Materials - Papers
The authors analyzed the thermionic cooling efficiency of the cylindrical semiconductor nanostructures. It is shown that due to the reduced emission current from the inner electrode, the cooling efficiency can be enhanced if the outer cylinder is the cold electrode. The threshold voltage for thermionic cooling is lower in cylindrical devices as compared to that in planar devices. The competition between the heat transport by electrons and the heat conduction by phonons is responsible for the efficiency enhancement and the voltage reduction.
Magnetic And Transport Properties Of Transition Metal Doped Polycrystalline In2o3, Germanas Peleckis, Xiaolin Wang, S X. Dou
Magnetic And Transport Properties Of Transition Metal Doped Polycrystalline In2o3, Germanas Peleckis, Xiaolin Wang, S X. Dou
Australian Institute for Innovative Materials - Papers
Synthesis and characterization of transition metal (TM)-doped In 2O3 oxide is reported. Most of the samples were found to be paramagnetic, and only Ye and Cr co-doped sample showed as light trace of ferromagnetism at 300 K with saturation magnetization M s = 0.35 emug/g. Measured transport properties revealed significant differences in transport among the samples. The absolute value of electrical resistivity for the In1.8Fe0.1Mn0.1O3 sample at 300 K was rho= 9.4 x 103 Omega middot cm, while In1.8Fe0.1Cr0.1O3 had rho = 62 …
Formation Of Magnesium Diboride-Based Materials With High Critical Currents And Mechanical Characteristics By High-Pressure Synthesis, Tetiana Prikhna, W. Gawalek, Ya M. Savchuk, N. V. Sergienko, V. E. Moshchil, M. Wendt, M. Zeisberger, T. Habisreuther, V. B. Sverdun, S X. Dou, S. N. Dub, V. S. Melnikov, Ch Schmidt, J. Dellith, P. A. Nagorny
Formation Of Magnesium Diboride-Based Materials With High Critical Currents And Mechanical Characteristics By High-Pressure Synthesis, Tetiana Prikhna, W. Gawalek, Ya M. Savchuk, N. V. Sergienko, V. E. Moshchil, M. Wendt, M. Zeisberger, T. Habisreuther, V. B. Sverdun, S X. Dou, S. N. Dub, V. S. Melnikov, Ch Schmidt, J. Dellith, P. A. Nagorny
Australian Institute for Innovative Materials - Papers
The developed method of high-pressure synthesis (HPS) allows producing nanostructural highly dense material based on MGB2, which possesses the highest superconducting and mechanical characteristics among the known world analogues, in the form of blocks that are suitable for application in SC electromotors and pumps. Additions of Zr can increase critical current density (jc) of synthesized at 2 GPa and 750-800 °C MGB2 in the same manner as additions of Ta or Ti, i.e. due to the absorption of impurity hydrogen forming the ZrH2. The formation of ZrB2 phase at higher synthesis …
Carbohydrate Doping To Enhance Electromagnetic Properties Of Mgb2 Superconductors, Jung Ho Kim, Sihai Zhou, Md S. Hossain, Alexey V. Pan, S X. Dou
Carbohydrate Doping To Enhance Electromagnetic Properties Of Mgb2 Superconductors, Jung Ho Kim, Sihai Zhou, Md S. Hossain, Alexey V. Pan, S X. Dou
Australian Institute for Innovative Materials - Papers
The effect of carbohydrate doping on lattice parameters, microstructure, Tc, Jc, Hirr, and Hc2 of MgB2 has been studied. In this work the authors used malic acid as an example of carbohydrates as an additive to MgB2. The advantages of carbohydrate doping include homogeneous mixing of precursor powders, avoidance of expansive nanoadditives, production of highly reactive C, and significant enhancement in Jc, Hirr, and Hc2 of MgB2, compared to undoped samples. The Jc for MgB2+30 wt% C4H6 …
Previous Heat Treatment Inducing Different Plasma Nitriding Behaviors In Martensitic Stainless Steels, C A. Figueroa, F Alvarez, D Rg Mitchell, G A. Collins, K T. Short
Previous Heat Treatment Inducing Different Plasma Nitriding Behaviors In Martensitic Stainless Steels, C A. Figueroa, F Alvarez, D Rg Mitchell, G A. Collins, K T. Short
Australian Institute for Innovative Materials - Papers
In this work we report a study of the induced changes in structure and corrosion behavior of martensitic stainless steels nitrided by plasma immersion ion implantation (PI3) at different previous heat treatments. The samples were characterized by x-ray diffraction and glancing angle x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and potentiodynamic measurements. Depending on the proportion of retained austenite in the unimplanted material, different phase transformations are obtained at lower and intermediate temperatures of nitrogen implantation. At higher temperatures, the great mobility of the chromium yields CrN segregations like spots in random distribution, and the a' -martensite is …
Electron Microscope Studies Of Al-Fe-Si Intermetallics In An A1-11 Percent Alloy, M V. Kral, P N H Nakashima, D Rg Mitchell
Electron Microscope Studies Of Al-Fe-Si Intermetallics In An A1-11 Percent Alloy, M V. Kral, P N H Nakashima, D Rg Mitchell
Australian Institute for Innovative Materials - Papers
Al-Fe-Si intermetallic particles in both unmodified and highly modified sand-cast eutectic AI-11.7 pct Si alloys were characterized using scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, and convergent beam and selected area electron diffraction. The only two Al-Fe-Si intermetallics observed in this particular alloy are (1) ‘‘Chinese-script’’ morphology, consistent with a description of body-centered cubic a-A119Fe4MNSi2 and (2) plate-shaped, consistent with tetragonal d-A1eFeSi2. The authors are unaware of any other characterization of d-A1eFeSi2 using convergent beam electron diffraction (CBED) and selected area diffraction (SAD) techniques.
1,8,14,20-Tetraoxa-11,23-Dithiatricyclo[21.3.0.09,13]Hexacosa-9,12,21,24-Tetraene, Pawel Wagner, Maciej Kubicki, Mieczyslaw Lapkowski
1,8,14,20-Tetraoxa-11,23-Dithiatricyclo[21.3.0.09,13]Hexacosa-9,12,21,24-Tetraene, Pawel Wagner, Maciej Kubicki, Mieczyslaw Lapkowski
Australian Institute for Innovative Materials - Papers
Crystals of the title compd. are orthorhombic, space group Pbca; Z = 4. Mols. lie on crystallog. centers of inversion, but have approx. C2h mol. symmetry. The parallel thiophene rings are almost exactly planar; the overall conformation of the mol. is chair-like. The mols. have voids that could, in principle, accommodate small guest mols., although in the crystal structure access to these voids is blocked by neighboring mols.
A Flip-Disorder In The Structure Of 3-[2-(Anthracen-9-Yl)Ethenyl]Thiophene, Pawel Wagner, David L. Officer, Maciej Kubicki
A Flip-Disorder In The Structure Of 3-[2-(Anthracen-9-Yl)Ethenyl]Thiophene, Pawel Wagner, David L. Officer, Maciej Kubicki
Australian Institute for Innovative Materials - Papers
In the crystal structure of the title compound, C20H14S, the thiophene rings are disordered; such a flip-type disorder is typical for simple, monosubstituted thiophene derivatives. Two planar fragments, the thiophene and the anthracene units, are almost perpendicular in order to relieve the H⋯H steric strains. The crystal packing is determined by van der Waals interactions, π–π stacking between the anthracene fragments, and some weak C—H⋯S and C—H⋯π short directional contacts.
2,5-Bis(2-Cyano-2-Thienylvinyl)Thiophene, Pawel Wagner, David L. Officer, Maciej Kubicki
2,5-Bis(2-Cyano-2-Thienylvinyl)Thiophene, Pawel Wagner, David L. Officer, Maciej Kubicki
Australian Institute for Innovative Materials - Papers
In the crystal structure of the title compound, C18H10N2S3, the terminal thiophene rings are disordered. This disorder is of a flip-type and has been observed in some other thiophene derivatives. The molecule as a whole is approximately planar; the dihedral angle between the terminal five-membered rings is 6.0 (2)°. The crystal packing is determined by van der Waals interactions, π–π stair-like stacking between the thiophene rings, and some weak C—H⋯S and C—H⋯π short directional contacts.
3-Methyl-5-Nitrouracil, Maciej Kubicki, Pawel Wagner
3-Methyl-5-Nitrouracil, Maciej Kubicki, Pawel Wagner
Australian Institute for Innovative Materials - Papers
The molecules of the title compound, C5H5N3O4, are approximately planar. The nitro group makes a dihedral angle of 1.3 (4)° with the plane of the six-membered ring. This coplanar disposition is a reason for the changes in valence angles in the vicinity of the nitro group. Molecules are connected into dimers by means of N—H⋯O hydrogen bonds, and these dimers make larger structures with the help of relatively short C—H⋯O hydrogen bonds.
Efficient Dye Sensitized Solar Cells Based On A 2-Thiophen-2-Yl-Vinyl-Conjugated Ruthenium Photosensitizer And A Conjugated Polymer Hole Conductor, Attila Mozer, Y Wada, K-J Jiang, N Masaki, S Yanagida, Shogo Mori
Efficient Dye Sensitized Solar Cells Based On A 2-Thiophen-2-Yl-Vinyl-Conjugated Ruthenium Photosensitizer And A Conjugated Polymer Hole Conductor, Attila Mozer, Y Wada, K-J Jiang, N Masaki, S Yanagida, Shogo Mori
Australian Institute for Innovative Materials - Papers
Efficient dye-sensitized TiO2 solar cells based on a 2-thiophen-2-yl-vinyl-conjugated ruthenium photosensitizer and a conjugated polymer poly(3,4-ethylenedioxythiophene) have been fabricated. A maximum power conversion efficiency of 2.6% is achieved when the mesoporous TiO2 layer is 5–6 μm. The high fill factor (0.74), the open circuit voltage (0.78V), and the linear light intensity dependence of the short circuit current density (4.5mA cm−2 at 100 mW cm−2) make these devices promising for solid state photovoltaic applications.
Electrochemical Study Of 1,3-Indandione Derivatives Of Terthiophenes, Mieczyslaw Lapkowski, Sylwia Plewa, Pawel Wagner, David L. Officer
Electrochemical Study Of 1,3-Indandione Derivatives Of Terthiophenes, Mieczyslaw Lapkowski, Sylwia Plewa, Pawel Wagner, David L. Officer
Australian Institute for Innovative Materials - Papers
Properties and behavior of a group of four newly synthesized derivatives of terthiophene and terthienylenvinylene was studied. All four investigated monomers bear a 1,3-indandione substituent at the central thiophene ring and two of them (ThIV, ThIVM) have additional vinyl bonds introduced between the thiophene rings. In addition, ThIM and ThIVM have 5 positions of the two terminal rings blocked with methyl groups. The measurements were done using cyclic voltamperometry (CV) in solutions of 0.1M Bu4NBF4 in CH2Cl2. It was found that ThI and ThIV polymerise easily. CV of ThI reveals a reduction peak …
Low-Cost Surface-Mount Led Gas Sensor, Roderick Shepherd, William S. Yerazunis, King Tong Lau, Dermot Diamond
Low-Cost Surface-Mount Led Gas Sensor, Roderick Shepherd, William S. Yerazunis, King Tong Lau, Dermot Diamond
Australian Institute for Innovative Materials - Papers
A low-cost chemical sensor comprising surface-mount light-emitting diodes (LEDs) has been developed for colorimetric gas detection. The device consists of a pair of LEDs connected to a simple PIC microcontroller circuit and in the most basic form, requires the use of only two input-output (I/O) pins on the chip. The key features of this sensor are the use of a LED rather than a photodiode for light detection and an all-digital light detection protocol that leads to a reduction in cost and power consumption by avoiding the need for an analog-to-digital converter. The surface-mount diodes employed are more compact than …
The Effect Of Oxidation On The Structure Of Styryl-Substituted Sexithiophenes: A Resonance Raman Spectroscopy And Density Functional Theory Study, Tracy Clarke, Keith Gordon, David L. Officer, Daina K. Grant
The Effect Of Oxidation On The Structure Of Styryl-Substituted Sexithiophenes: A Resonance Raman Spectroscopy And Density Functional Theory Study, Tracy Clarke, Keith Gordon, David L. Officer, Daina K. Grant
Australian Institute for Innovative Materials - Papers
The structures and vibrational properties of a series of styryl-substituted sexithiophenes and their charged species have been examined using resonance Raman spectroscopy in conjunction with density functional theory calculations. The calculated geometries of the radical cations and dications indicate that the quinoidal charged defects are more strongly localized in the center of the thiophene backbone than is observed in other sexithiophenes. This defect confinement, induced by the positions of the styryl substituents, is particularly evident in the dication species. However, the defect confinement weakens when alkoxy groups are added onto the phenyl rings by causing the extension of the charged …
Growth Of Width-Controlled Nanowires Mno2 From Mesoporous Carbon And Investigation Of Their Properties, Shenmin Zhu, Xiaolin Wang, Wei Huang, Deyue Yan, Honghua Wang, Di Zhang
Growth Of Width-Controlled Nanowires Mno2 From Mesoporous Carbon And Investigation Of Their Properties, Shenmin Zhu, Xiaolin Wang, Wei Huang, Deyue Yan, Honghua Wang, Di Zhang
Australian Institute for Innovative Materials - Papers
One-dimensional α-MnO2 nanowires with a controlled width of 10–20 nm have been developed by means of ultrasonic waves from mesoporous carbon using KMnO4 as the precursor. The formation mechanism has been proposed based on the results. A peak around 100 K was detected in the temperature-dependence of magnetization curve, indicating the ferromagnetic state in nanocomposite mesoporous carbon-MnO2, which is in agreement with the transition temperature found from the magnetization versus applied magnetic field curve. The magnetization versus temperature curve of the obtained MnO2 nanowires showed a magnetic transition at about 50 K, illustrating that a …
Spin Singlet Pairing In The Superconducting State Of Naxco02 1.3h2o: Evidence From A 59co Knight Shift In A Single Crystal, Guo-Qing Zheng, Kazuaki Matano, Dapeng Chen, C T. Lin
Spin Singlet Pairing In The Superconducting State Of Naxco02 1.3h2o: Evidence From A 59co Knight Shift In A Single Crystal, Guo-Qing Zheng, Kazuaki Matano, Dapeng Chen, C T. Lin
Australian Institute for Innovative Materials - Papers
We report a 59Co Knight-shift measurement in a single crystal of the cobalt oxide superconductor NaxCoO2∙1.3H2O (Tc=4.25 K). We find that the shift due to the spin susceptibility, Ks, is substantially large and anisotropic, with the spin shift along the a-axis Kas being two times that along the c-axis Kcs. The shift decreases with decreasing temperature (T) down to T≈100 K, then becomes a constant until superconductivity sets in. Both Kas and Kcs decrease below Tc. Our results indicate unambiguously that the electron pairing in the superconducting state is in the spin singlet form.
Anomalous Electronic Raman Scattering In Naxcoo2. Yh2o, P Lemmens, K. Y. Choi, E Sherman, Dapeng Chen, C T Lin, F. C. Chou, B Keimer
Anomalous Electronic Raman Scattering In Naxcoo2. Yh2o, P Lemmens, K. Y. Choi, E Sherman, Dapeng Chen, C T Lin, F. C. Chou, B Keimer
Australian Institute for Innovative Materials - Papers
Raman scattering experiments on NaxCoO2·yH2O single crystals show a broad electronic continuum with a pronounced peak around 100 cm-1 and a cutoff at approximately 560 cm-1 over a wide range of doping levels. The electronic Raman spectra in superconducting and nonsuperconducting samples are similar at room temperature, but evolve in markedly different ways with decreasing temperature. For superconducting samples, the low-energy spectral weight is depleted upon cooling below T*∼150 K, indicating the opening of a pseudogap that is not present in nonsuperconducting materials. Weak additional phonon modes observed below T* suggest that the pseudogap is associated with charge ordering.
Solid State Ph Sensor Based On Light Emitting Diodes (Led) As Detector Platform, King Tong Lau, Roderick Shepherd, Danny Diamond, Dermot Diamond
Solid State Ph Sensor Based On Light Emitting Diodes (Led) As Detector Platform, King Tong Lau, Roderick Shepherd, Danny Diamond, Dermot Diamond
Australian Institute for Innovative Materials - Papers
A low-power, high sensitivity, very low-cost light emitting diode (LED)-based device developed for low-cost sensor networks was modified with bromocresol green membrane to work as a solid-state pH sensor. In this approach, a reverse-biased LED functioning as a photodiode is coupled with a second LED configured in conventional emission mode. A simple timer circuit measures how long (in microsecond) it takes for the photocurrent generated on the detector LED to discharge its capacitance from logic 1 (+5 V) to logic 0 (+1.7 V). The entire instrument provides an inherently digital output of light intensity measurements for a few cents. A …
Comparison Of Small-Field Behaviour In Mgb2, Low And High Temperature Superconductors, Alexey V. Pan, S X. Dou
Comparison Of Small-Field Behaviour In Mgb2, Low And High Temperature Superconductors, Alexey V. Pan, S X. Dou
Australian Institute for Innovative Materials - Papers
Different types of superconductors have been investigated at small magnetic fields (Ba) over wide temperature (T) ranges at different Ba orientations. It has been shown that the temperature dependence of the characteristic field (B*), separating the Ba-independent critical current density (Jc) plateau (single vortex pinning regime) and the region with Jc(Ba) (collective pinning), can be attributed either to the temperature dependence of the magnetic penetration depth for Nb-film and MgB2bulk superconductors, or to thermally activated processes for Bi-based superconductors and YBa2Cu3O7−δ superconducting …
Influence Of The Iron Sheath On The Local Supercurrent Distribution In Mgb2 Wires, Marie Roussel, Alexey V. Pan, Sihai Zhou, S X. Dou
Influence Of The Iron Sheath On The Local Supercurrent Distribution In Mgb2 Wires, Marie Roussel, Alexey V. Pan, Sihai Zhou, S X. Dou
Australian Institute for Innovative Materials - Papers
The magnetic behavior of iron sheathed magnesium diboride (MgB2) wires was investigated. Global magnetization measurements have shown unusual critical current density variations compare to a superconductor with no magnetic environment. Local quantitative studies, through MO images, are linked to these global magnetization measurements in order to better understand the observed results. It is shown that the current distribution is affected by the soft magnetic sheath interacting with the superconducting core.