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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Modulation Of The Properties Of Thin Ferromagnetic Films With An Externally Applied Electric Field In Ferromagnetic/Piezoelectric/Ferromagnetic Hybrids, D Stamopoulos, M Zeibekis, Shujun Zhang
Modulation Of The Properties Of Thin Ferromagnetic Films With An Externally Applied Electric Field In Ferromagnetic/Piezoelectric/Ferromagnetic Hybrids, D Stamopoulos, M Zeibekis, Shujun Zhang
Australian Institute for Innovative Materials - Papers
In many cases, technological advances are based on artificial low-dimensional structures of heterogeneous constituents, thus called hybrids, that when come together they provide stand-alone entities that exhibit entirely different properties. Such hybrids are nowadays intensively studied since they are attractive for both basic research and oncoming practical applications. Here, we studied hybrids constituted of piezoelectric (PE) and ferromagnetic (FM) components in the form FM/PE/FM, ultimately aiming to provide means for the controlled modulation of the properties of the FM electrodes, originating from the strain imposed to them by the PE mediator when an electric field is applied. The PE component …
Nanosecond Voltage Pulses From Dendritic Flux Avalanches In Superconducting Nbn Films, P Mikheenko, A J. Qviller, J I. Vestgarden, S Chaudhuri, I J. Maasilta, Y M. Galperin, Tom H. Johansen
Nanosecond Voltage Pulses From Dendritic Flux Avalanches In Superconducting Nbn Films, P Mikheenko, A J. Qviller, J I. Vestgarden, S Chaudhuri, I J. Maasilta, Y M. Galperin, Tom H. Johansen
Australian Institute for Innovative Materials - Papers
Combined voltage and magneto-optical study of magnetic flux flow in superconducting NbN films is reported. The nanosecond-scale voltage pulses appearing during thermomagnetic avalanches have been recorded in films partially coated by a metal layer. Simultaneous magneto-optical imaging and voltage measurements allowed the pulses to be associated with individual flux branches penetrating the superconductor below the metal coating. From detailed characteristics of pulse and flux branches, the electrical field in the superconductor is found to be in the range of 5-50 kV/m, while the propagation speed of the avalanche during its final stage is found to be close to 5 km/s.
Enhanced Pinning In Superconducting Thin Films With Graded Pinning Landscapes, M Motta, F Colauto, W A. Ortiz, J Fritzsche, J Cuppens, W Gillijns, V V. Moshchalkov, T H. Johansen, A W Sanchez, A Silhanek
Enhanced Pinning In Superconducting Thin Films With Graded Pinning Landscapes, M Motta, F Colauto, W A. Ortiz, J Fritzsche, J Cuppens, W Gillijns, V V. Moshchalkov, T H. Johansen, A W Sanchez, A Silhanek
Australian Institute for Innovative Materials - Papers
A graded distribution of antidots in superconducting a-Mo 79Ge21 thin films has been investigated by magnetization and magneto-optical imaging measurements. The pinning landscape has maximum density at the sample border, decreasing linearly towards the center. Its overall performance is noticeably superior than that for a sample with uniformly distributed antidots: For high temperatures and low fields, the critical current is enhanced, whereas the region of thermomagnetic instabilities in the field-temperature diagram is significantly suppressed. These findings confirm the relevance of graded landscapes on the enhancement of pinning efficiency, as recently predicted by Misko and Nori [Phys. Rev. B 85, 184506 …
Thermoelectric Properties Of Ca3co4o9 And Ca2.8bi0.2co4o9 Thin Films In Their Island Formation Mode, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou
Thermoelectric Properties Of Ca3co4o9 And Ca2.8bi0.2co4o9 Thin Films In Their Island Formation Mode, Priyanka Jood, Germanas Peleckis, Xiaolin Wang, S X. Dou
Australian Institute for Innovative Materials - Papers
Ca3Co4O9 and Ca2.8Bi 0.2Co4O9 thin films were fabricated on LaAlO3 (LAO) substrate using pulsed laser deposition technique and were studied for their thermoelectric (TE) properties in Stranski-Krastanov mode for the first time. The thin films consisted of 3D clusters/islands on a 14-nm thick 2D layer with cluster density being higher for Ca 2.8Bi0.2Co4O9 thin films. The clusters also represent areas of dislocation and therefore act as carrier scattering centers, which leads to a temperature-activated type conductivity. Seebeck coefficient as high as 136 and 163 u V/K was measured for the Ca 3Co4O9 and Ca2.8Bi 0.2Co4O9 thin films, respectively, which is …
Facile Synthesis Of Reduced Graphene Oxide/Mwnts Nanocomposite Supercapacitor Materials Tested As Electrophoretically Deposited Films On Glassy Carbon Electrodes, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Byung C. Kim, Rao Yepuri, Anthony C. Romeo, Gordon G. Wallace
Facile Synthesis Of Reduced Graphene Oxide/Mwnts Nanocomposite Supercapacitor Materials Tested As Electrophoretically Deposited Films On Glassy Carbon Electrodes, Widsanusan Chartarrayawadee, Simon E. Moulton, Chee O. Too, Byung C. Kim, Rao Yepuri, Anthony C. Romeo, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
This paper reports on a facile synthesis method for reduced graphene oxide (rGO)/multi-walled carbon nanotubes (MWNTs) nanocomposites. The initial step involves the use of graphene oxide to disperse the MWNTs, with subsequent reduction of the resultant graphene oxide/MWNTs composites using l-ascorbic acid (LAA) as a mild reductant. Reduction by LAA preserves the interaction between the rGO sheets and MWNTs. The dispersion-containing rGO/MWNTs composites was characterized and electrophoretically deposited anodically onto glassy carbon electrodes to form high surface area films for capacitance testing. Pseudo capacitance peaks were observed in the rGO/MWNTs composite electrodes, resulting in superior performance with capacitance values up …
Crystallization, Phase Evolution And Ferroelectric Properties Of Sol-Gel-Synthesized Ba(Ti0.8zr0.2)O3- X(Ba0.7ca0.3)Tio3 Thin Films, Zeng-Mei Wang, Kuan Zhao, Xin-Li Guo, Wei Sun, Hua-Long Jiang, Xue-Qin Han, Xu-Tang Tao, Zhen-Xiang Cheng, Hong-Yang Zhao, Hideo Kimura, Guo-Liang Yuan, Jiang Yin, Zhi-Guo Liu
Crystallization, Phase Evolution And Ferroelectric Properties Of Sol-Gel-Synthesized Ba(Ti0.8zr0.2)O3- X(Ba0.7ca0.3)Tio3 Thin Films, Zeng-Mei Wang, Kuan Zhao, Xin-Li Guo, Wei Sun, Hua-Long Jiang, Xue-Qin Han, Xu-Tang Tao, Zhen-Xiang Cheng, Hong-Yang Zhao, Hideo Kimura, Guo-Liang Yuan, Jiang Yin, Zhi-Guo Liu
Australian Institute for Innovative Materials - Papers
A lead-free piezoelectric material with ultra-high properties, Ba(Ti0.8Zr0.2)O3-x(Ba0.7Ca0.3)TiO3(BZT-xBCT) nanocrystals was synthesized via a sol-gel method, and the corresponding thin films were also deposited on Pt/Ti/SiO2/Si substrates by a spin-coating approach. The BZT-xBCT thin film exhibited a high remnant polarization of 22.15 mC cm2 with a large coercive field of 68.06 kV cm1. The resultant gel is calcined at various elevated temperatures and studied with FTIR/XRD/Raman/DSC-TGA/AFM/SEM techniques for gel composition, crystallization, phase transition, thermochemistry and the morphology of the film. Although the room temperature crystal structure of the BZT-xBCT nanocrystals appears to be a standard perovskite structure by conventional X-ray diffraction …
Anisotropy Of Crystal Growth Mechanisms, Dielectricity, And Magnetism Of Multiferroic Bi2femno6 Thin Films, P Liu, Z X. Cheng, Y Du, L Y. Feng, H Fang, Xiaolin Wang, S X. Dou
Anisotropy Of Crystal Growth Mechanisms, Dielectricity, And Magnetism Of Multiferroic Bi2femno6 Thin Films, P Liu, Z X. Cheng, Y Du, L Y. Feng, H Fang, Xiaolin Wang, S X. Dou
Australian Institute for Innovative Materials - Papers
Epitaxial Bi2FeMnO6 (BFMO) thin films deposited on various Nb:SrTiO3 substrates show that the lattice parameters are very sensitive to epitaxial strains. Compressive and tensile strains are induced to the in-plane lattice constants of the (100) and (111) oriented films, respectively, while that of the (110) oriented thin film stay unstrained. The thin films also exhibit a strongly anisotropic growth habit depending on the substrate. Spiral growth, such as in the (100) BFMO film, is unique in samples prepared by pulsed laser deposition. Extrinsic dielectric constants at low frequencies are attributed to oxygen vacancies via the Maxwell-Wagner effect. All the samples …
Thermo-Magnetic Stability Of Superconducting Films Controlled By Nano-Morphology, V V. Yurchenko, K Ilin, J M. Meckbach, M Siegel, A J. Qviller, Y M. Galperin, Tom H. Johansen
Thermo-Magnetic Stability Of Superconducting Films Controlled By Nano-Morphology, V V. Yurchenko, K Ilin, J M. Meckbach, M Siegel, A J. Qviller, Y M. Galperin, Tom H. Johansen
Australian Institute for Innovative Materials - Papers
Appearance of dendritic magnetic flux avalanches in superconducting films, which are associated with thermo-magnetic instability (TMI), very often indicates serious limitations for the ultimate performance of superconducting devices made of type-II superconducting thin films. We demonstrate that the stability can be controlled by a thorough adjustment of samples morphology at nano-scale, which affects internal material parameters. By this, the metal coating, commonly used as for stabilization, becomes redundant. Most importantly, we directly show by the mean of magneto-optical imaging that introduction of nano-scaled disorder dramatically changes the mode of magnetic flux propagation in the superconductors, from uniform motion of individual …
Limiting Thermomagnetic Avalanches In Superconducting Films By Stop-Holes, F Colauto, J I. Vestgarden, A M H De Andrade, A A M Oliveira, Wilson Aires Ortiz, Tom H. Johansen
Limiting Thermomagnetic Avalanches In Superconducting Films By Stop-Holes, F Colauto, J I. Vestgarden, A M H De Andrade, A A M Oliveira, Wilson Aires Ortiz, Tom H. Johansen
Australian Institute for Innovative Materials - Papers
It is demonstrated that circular holes in superconducting films of Nb can arrest the propagation of thermomagnetic avalanches. The effect was found over a range of temperatures where the material is susceptible to this instability. For other hole shapes, like square and triangular, the sharp corners provoke secondary avalanches, thus extending the breakdown. Making use of circular stop-holes can become a practical way to limit thermomagnetic breakdown in superconducting films.
Nonlocal Electrodynamics Of Normal And Superconducting Films, J I. Vestgarden, P Mikheenko, Y M. Galperin, T H Johansen
Nonlocal Electrodynamics Of Normal And Superconducting Films, J I. Vestgarden, P Mikheenko, Y M. Galperin, T H Johansen
Australian Institute for Innovative Materials - Papers
Electrically conducting films in a time-varying transverse applied magnetic field are considered. Their behavior is strongly influenced by the self-field of the induced currents, making the electrodynamics nonlocal, and consequently difficult to analyze both numerically and analytically. We present a formalism which allows many phenomena related to superconducting and Ohmic films to be modeled and analyzed. The formalism is based on the Maxwell equations and a material current-voltage characteristics, linear for normal metals and nonlinear for superconductors, plus a careful account of the boundary conditions. For Ohmic films, we consider the response to a delta function source-field turned on instantly. …
Flexible Cellulose Based Polypyrrole-Multiwalled Carbon Nanotube Films For Bio-Compatible Zinc Batteries Activated By Simulated Body Fluids, Sha Li, Zai Ping Guo, Cai Yun Wang, Gordon G. Wallace, Hua-Kun Liu
Flexible Cellulose Based Polypyrrole-Multiwalled Carbon Nanotube Films For Bio-Compatible Zinc Batteries Activated By Simulated Body Fluids, Sha Li, Zai Ping Guo, Cai Yun Wang, Gordon G. Wallace, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
This work aims to develop biocompatible non-toxic materials for implantable bio-electronic cells. Polypyrrole (PPy)–carbon nanotube (CNT) composites with varied ratios of PPy to CNTs were chemically synthesized and used as cathodes with the support of cellulose paper. Zinc foil was used as the anode material due to its non-toxicity and moderate dissolution rate in aqueous solutions. Simulated body fluids (SBFs) with various protein concentrations were applied as electrolytes in this battery system. The PPy–CNT|Zn cell is capable of being discharged up to 24.5 hours at a current density of 60 μA cm−2 in a protein free SBF. The batteries …