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Full-Text Articles in Physical Sciences and Mathematics
Dynamic Magneto-Optical Imaging Of Superconducting Thin Films, Frederick Wells, Alexey V. Pan, Stephen Wilson, Igor Golovchanskiy, Sergey Fedoseev, Anatoly B. Rosenfeld
Dynamic Magneto-Optical Imaging Of Superconducting Thin Films, Frederick Wells, Alexey V. Pan, Stephen Wilson, Igor Golovchanskiy, Sergey Fedoseev, Anatoly B. Rosenfeld
Australian Institute for Innovative Materials - Papers
We present a novel method for analysis of superconducting thin films using dynamic magneto-optical imaging, revealing hallmarks of flux penetration with temporal resolution around 1 ms (in the present work) or better. This method involves investigation of transient field and dynamic current distributions, which are calculated by an inversion procedure on the Biot-Savart Law, which we show to be valid under dynamic conditions. We compare and discuss the flux front penetration speed and evolution of current distribution in high quality YBa2Cu3O${}_{7-\delta }$ thin films with that of samples deliberately damaged in such a way as to reduce critical current density …
Tuning Superconductivity In Fese Thin Films Via Magnesium Doping, Wenbin Qiu, Zongqing Ma, Yongchang Liu, Md Shahriar Hossain, Xiaolin Wang, Chuanbing Cai, S X. Dou
Tuning Superconductivity In Fese Thin Films Via Magnesium Doping, Wenbin Qiu, Zongqing Ma, Yongchang Liu, Md Shahriar Hossain, Xiaolin Wang, Chuanbing Cai, S X. Dou
Australian Institute for Innovative Materials - Papers
In contrast to its bulk crystal, the FeSe thin film or layer exhibits better superconductivity performance, which recently attracted much interest in its fundamental research as well as in potential applications around the world. In the present work, tuning superconductivity in FeSe thin films was achieved by magnesium-doping technique. Tc is significantly enhanced from 10.7 K in pure FeSe films to 13.4 K in optimized Mg-doped ones, which is approximately 1.5 times higher than that of bulk crystals. This is the first time achieving the enhancement of superconducting transition temperature in FeSe thin films with practical thickness (120 nm) via …
Conductive And Protein Resistant Polypyrrole Films For Dexamethasone Delivery, Binbin Zhang, Paul J. Molino, Alexander R. Harris, Zhilian Yue, Simon E. Moulton, Gordon G. Wallace
Conductive And Protein Resistant Polypyrrole Films For Dexamethasone Delivery, Binbin Zhang, Paul J. Molino, Alexander R. Harris, Zhilian Yue, Simon E. Moulton, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
The development of inherently conducting polymers as controllable/programmable drug delivery systems has attracted significant interest in medical bionics, and the interfacial properties of the polymers, in particular, protein adsorption characteristics, is integral to the stability of the overall performance. Herein we report a hybrid conducting system based on polypyrrole doped with an anti-inflammatory prodrug, dexamethasone phosphate (DexP), upon which post-surface modification was conducted to render the polymer more biostable. We firstly investigated the influence of the current density and DexP concentration on the physiochemical properties and surface characteristics of the resulting polymer films. Films were then surface modified with thiolated …
Metal Frame As Local Protection Of Superconducting Films From Thermomagnetic Avalanches, Pavlo Mikheenko, J I. Vestgarden, Supratim Chaudhuri, I J. Maasilta, Y Galperin, Tom H. Johansen
Metal Frame As Local Protection Of Superconducting Films From Thermomagnetic Avalanches, Pavlo Mikheenko, J I. Vestgarden, Supratim Chaudhuri, I J. Maasilta, Y Galperin, Tom H. Johansen
Australian Institute for Innovative Materials - Papers
Thermomagnetic avalanches in superconducting films propagating extremely fast while forming unpredictable patterns, represent a serious threat for the performance of devices based on such materials. It is shown here that a normal-metal frame surrounding a selected region inside the film area can provide efficient protection from the avalanches during their propagation stage. Protective behavior is confirmed by magneto-optical imaging experiments on NbN films equipped with Cu and Al frames, and also by performing numerical simulations. Experimentally, it is found that while conventional flux creep is not affected by the frames, the dendritic avalanches are partially or fully screened by them. …
Interface-Enhanced Electron-Phonon Coupling And High-Temperature Superconductivity In Potassium-Coated Ultrathin Fese Films On Srtio3, Chenjia Tang, Chong Liu, Guanyu Zhou, Fangsen Li, Hao Ding, Zhi Li, Ding Zhang, Zheng Li, Canli Song, Shuaihua Ji, Ke He, Lili Wang, Xucan Ma, Qi-Kun Xue
Interface-Enhanced Electron-Phonon Coupling And High-Temperature Superconductivity In Potassium-Coated Ultrathin Fese Films On Srtio3, Chenjia Tang, Chong Liu, Guanyu Zhou, Fangsen Li, Hao Ding, Zhi Li, Ding Zhang, Zheng Li, Canli Song, Shuaihua Ji, Ke He, Lili Wang, Xucan Ma, Qi-Kun Xue
Australian Institute for Innovative Materials - Papers
Alkali-metal (potassium) adsorption on FeSe thin films with thickness from 2 unit cells (UC) to 4 UC on SrTiO3 grown by molecular beam epitaxy is investigated with a low-temperature scanning tunneling microscope. At appropriate potassium coverage (0.20-0.25 monolayer), the tunneling spectra of the films all exhibit a superconductinglike gap which is overall larger than 11 meV (five times the gap value of bulk FeSe) and decreases with increasing thickness, and two distinct features of characteristic phonon modes at ∼11 and ∼21 meV. The results reveal the critical role of the interface-enhanced electron-phonon coupling for possible high-temperature superconductivity in ultrathin FeSe …
Strain-Induced Magnetic Phase Transition In Srcoo3−Δ Thin Films, S J. Callori, S Hu, Joel Bertinshaw, Zhilian Yue, S Danilkin, Xiaolin Wang, V Nagarajan, Frank Klose, Jan Seidel, Clemens Ulrich
Strain-Induced Magnetic Phase Transition In Srcoo3−Δ Thin Films, S J. Callori, S Hu, Joel Bertinshaw, Zhilian Yue, S Danilkin, Xiaolin Wang, V Nagarajan, Frank Klose, Jan Seidel, Clemens Ulrich
Australian Institute for Innovative Materials - Papers
It has been well established that both in bulk at ambient pressure and for films under modest strains, cubic SrCoO3−δ (δ<0.2) is a ferromagnetic metal. Recent theoretical work, however, indicates that a magnetic phase transition to an antiferromagnetic structure could occur under large strain accompanied by a metal-insulator transition. We have observed a strain-induced ferromagnetic-to-antiferromagnetic phase transition in SrCoO3−δ films grown on DyScO3 substrates, which provide a large tensile epitaxial strain, as compared to ferromagnetic films under lower tensile strain on SrTiO3 substrates. Magnetometry results demonstrate the existence of antiferromagnetic spin correlations and neutron diffraction experiments provide a direct evidence for a G-type antiferromagnetic structure with Neél temperatures between TN∼135±10K and ∼325±10K, depending on the oxygen content of the samples. Therefore, our data experimentally confirm the predicted strain-induced magnetic phase transition to an antiferromagnetic state for SrCoO3−δ thin films under large epitaxial strain.
Ferroelectric And Magnetic Properties Of Aurivillius Bim+1ti3fem−3o3m+3 Thin Films, Tingting Jia, Hideo Kimura, Zhenxiang Cheng, Hongyang Zhao
Ferroelectric And Magnetic Properties Of Aurivillius Bim+1ti3fem−3o3m+3 Thin Films, Tingting Jia, Hideo Kimura, Zhenxiang Cheng, Hongyang Zhao
Australian Institute for Innovative Materials - Papers
Aurivillius Bim+1Ti3Fem−3O3m+3 (m = 4, 5, 6) thin films have been deposited by a pulsed laser deposition system. The x-ray diffraction patterns indicate the formation of orthorhombic phase. The remanent polarization (2Pr) of Bim+1Ti3Fem−3O3m+3 thin films is decreased with the m-number. Positive-up-negative-down measurements indicate the presence of ferroelectric (FE) polarization in as-obtained thin films. Piezoresponse force microscopy investigations confirm the existence of FE domains and the switchable polarization. Weak magnetic moment is detected in the Aurivillius films at room temperature. The present work …
Free-Standing Composite Hydrogel Films For Superior Volumetric Capacitance, Mahmoud Moussa, Zhiheng Zhao, Maher F. El-Kady, Hua-Kun Liu, Andrew Michelmore, Nobuyuki Kawashima, Peter Majewski, Jun Ma
Free-Standing Composite Hydrogel Films For Superior Volumetric Capacitance, Mahmoud Moussa, Zhiheng Zhao, Maher F. El-Kady, Hua-Kun Liu, Andrew Michelmore, Nobuyuki Kawashima, Peter Majewski, Jun Ma
Australian Institute for Innovative Materials - Papers
High volumetric capacitance is vital for the development of wearable and portable energy storage devices. We herein introduce a novel simple route for the fabrication of a highly porous, binder-free and free-standing polyaniline/reduced graphene oxide composite hydrogel (PANi/graphene hydrogel) as an electrode with a packing density of 1.02 g cm-3. PANi played critical roles in gelation, which include reduction, crosslinking, creation of pseudocapacitance and as a spacer preventing graphene sheets from stacking. The composite hydrogel film delivered a volumetric capacitance of 225.42 F cm-3 with a two-electrode supercapacitor configuration, which was enhanced to 592.96 F cm-3 …
A Facile Approach For Fabrication Of Mechanically Strong Graphene/Polypyrrole Films With Large Areal Capacitance For Supercapacitor Applications, Yu Ge, Caiyun Wang, Kewei Shu, Chen Zhao, Xiaoteng Jia, Sanjeev Gambhir, Gordon G. Wallace
A Facile Approach For Fabrication Of Mechanically Strong Graphene/Polypyrrole Films With Large Areal Capacitance For Supercapacitor Applications, Yu Ge, Caiyun Wang, Kewei Shu, Chen Zhao, Xiaoteng Jia, Sanjeev Gambhir, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Substantial progress has been made in free-standing flexible graphene-based films for flexible supercapacitors. However, there are limited reports on the areal capacitance of these electrodes, which is an important parameter for practical applications, especially in miniaturized electronic devices. Herein we report the facile fabrication of robust flexible graphene/polypyrrole nanoparticle films. PPy NPs act as the "spacer" between graphene layers creating hierarchical structures. This free-standing film shows excellent mechanical properties with a fracture strength of 16.89 MPa and Young's modulus of 11.77 MPa. The resulting film electrode delivers a large areal specific capacitance of 216 mF cm−2, which is higher or …
In Situ Anchoring Uniform Mno2 Nanosheets On Three-Dimensional Macroporous Graphene Thin-Films For Supercapacitor Electrodes, Yong Zhao, Yuena Meng, Haiping Wu, Yue Wang, Zhixiang Wei, Xiaojun Li, Peng Jiang
In Situ Anchoring Uniform Mno2 Nanosheets On Three-Dimensional Macroporous Graphene Thin-Films For Supercapacitor Electrodes, Yong Zhao, Yuena Meng, Haiping Wu, Yue Wang, Zhixiang Wei, Xiaojun Li, Peng Jiang
Australian Institute for Innovative Materials - Papers
We present a facile and efficient fabrication of 3D macroporous rGO/MnO2 nanosheet thin-films for supercapacitor electrodes. An amorphous-carbon-modified rGO thin-film is firstly prepared through a simple glucose and CaCO3 particle mediated template method. Then ultrathin MnO2 nanosheets are in situ synthesized on the rGO networks by the rapid and scalable redox reaction between KMnO4 and amorphous carbon. The fabricated three-dimensional porous hybrid thin-film shows a high specific capacitance of 245 F g-1 (based on the total mass of the film) at a scan rate of 2 mV s-1, a good rate capability of 143 F g-1 at 300 mV s-1, …
High-Performance Flexible All-Solid-State Supercapacitor From Large Free-Standing Graphene-Pedot/Pss Films, Yuqing Liu, Bo Weng, Joselito M. Razal, Qun Xu, Chen Zhao, Yuyang Hou, Shayan Seyedin, Rouhollah Jalili, Gordon G. Wallace, Jun Chen
High-Performance Flexible All-Solid-State Supercapacitor From Large Free-Standing Graphene-Pedot/Pss Films, Yuqing Liu, Bo Weng, Joselito M. Razal, Qun Xu, Chen Zhao, Yuyang Hou, Shayan Seyedin, Rouhollah Jalili, Gordon G. Wallace, Jun Chen
Australian Institute for Innovative Materials - Papers
Although great attention has been paid to wearable electronic devices in recent years, flexible lightweight batteries or supercapacitors with high performance are still not readily available due to the limitations of the flexible electrode inventory. In this work, highly flexible, bendable and conductive rGO-PEDOT/PSS films were prepared using a simple bar-coating method. The assembled device using rGO-PEDOT/PSS electrode could be bent and rolled up without any decrease in electrochemical performance. A relatively high areal capacitance of 448 mF cm-2 was achieved at a scan rate of 10 mV s-1 using the composite electrode with a high mass loading (8.49 mg …
Protein Nanorings Organized By Poly(Styrene-Block-Ethylene Oxide) Self-Assembled Thin Films, Jenny Malmström, Akshita Wason, Fergus Roache, N. Amy Yewdall, Mazdak Radjainia, Shanghai Wei, Michael J. Higgins, David Williams, Juliet A. Gerrard, Jadranka Travas-Sejdic
Protein Nanorings Organized By Poly(Styrene-Block-Ethylene Oxide) Self-Assembled Thin Films, Jenny Malmström, Akshita Wason, Fergus Roache, N. Amy Yewdall, Mazdak Radjainia, Shanghai Wei, Michael J. Higgins, David Williams, Juliet A. Gerrard, Jadranka Travas-Sejdic
Australian Institute for Innovative Materials - Papers
This study explores the use of block copolymer self-assembly to organize Lsmα, a protein which forms stable doughnut-shaped heptameric structures. Here, we have explored the idea that 2-D crystalline arrays of protein filaments can be prepared by stacking doughnut shaped Lsmα protein into the poly(ethylene oxide) blocks of a hexagonal microphase-separated polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer. We were able to demonstrate the coordinated assembly of such a complex hierarchical nanostructure. The key to success was the choice of solvent systems and protein functionalization that achieved sufficient compatibility whilst still promoting assembly. Unambiguous characterisation of these structures is difficult; however AFM …
An Investigation Of The Nanomechanical Properties Of 0.5ba(Ti0.8zr0.2)O3-0.5(Ba0.7ca0.3)Tio3 Thin Films, Zhong-Lan Cai, Zeng-Mei Wang, Huan-Huan Wang, Zhenxiang Cheng, Baowen Li, Xin-Li Guo, Hideo Kimura, Akira Kasahara
An Investigation Of The Nanomechanical Properties Of 0.5ba(Ti0.8zr0.2)O3-0.5(Ba0.7ca0.3)Tio3 Thin Films, Zhong-Lan Cai, Zeng-Mei Wang, Huan-Huan Wang, Zhenxiang Cheng, Baowen Li, Xin-Li Guo, Hideo Kimura, Akira Kasahara
Australian Institute for Innovative Materials - Papers
For practical application, the functional piezoelectric film in microelectromechanical systems should meet the requirement of physical properties, as well as the mechanical properties. In this article, 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 (0.5BZT-0.5BCT) thin films with varied properties were prepared on (100) Si substrates via a sol-gel technique at different annealing temperatures. The effects of the annealing temperature on the morphology, piezoelectricity, hardness, and elastic modulus were studied. Particular attention was paid to the surface frictional behavior of films, and the changes in the friction force can be radically explained in terms of differences in the hardness/elastic modulus ratio and the residual stress of films. …
Analysis Of Low-Field Isotropic Vortex Glass Containing Vortex Groups In Yba2cu3o7−X Thin Films Visualized By Scanning Squid Microscopy, Frederick Wells, Alexey V. Pan, Renshaw Wang, Sergey Fedoseev, Hans Hilgenkamp
Analysis Of Low-Field Isotropic Vortex Glass Containing Vortex Groups In Yba2cu3o7−X Thin Films Visualized By Scanning Squid Microscopy, Frederick Wells, Alexey V. Pan, Renshaw Wang, Sergey Fedoseev, Hans Hilgenkamp
Australian Institute for Innovative Materials - Papers
The glass-like vortex distribution in pulsed laser deposited YBa2Cu3O7 − x thin films is observed by scanning superconducting quantum interference device microscopy and analysed for ordering after cooling in magnetic fields significantly smaller than the Earth's field. Autocorrelation calculations on this distribution show a weak short-range positional order, while Delaunay triangulation shows a near-complete lack of orientational order. The distribution of these vortices is finally characterised as an isotropic vortex glass. Abnormally closely spaced groups of vortices, which are statistically unlikely to occur, are observed above a threshold magnetic field. The origin of these groups …
Ray Optics Behavior Of Flux Avalanche Propagation In Superconducting Films, Pavlo Mikheenko, Tom H. Johansen, Supratim Chaudhuri, I J. Maasilta, Y Galperin
Ray Optics Behavior Of Flux Avalanche Propagation In Superconducting Films, Pavlo Mikheenko, Tom H. Johansen, Supratim Chaudhuri, I J. Maasilta, Y Galperin
Australian Institute for Innovative Materials - Papers
Experimental evidence of wave properties of dendritic flux avalanches in superconducting films is reported. Using magneto-optical imaging the propagation of dendrites across boundaries between a bare NbN film and areas coated by a Cu layer was visualized, and it was found that the propagation is refracted in full quantitative agreement with Snell's law. For the studied film of 170 nm thickness and a 0.9μm thick metal layer, the refractive index was close to n=1.4. The origin of the refraction is believed to be caused by the dendrites propagating as an electromagnetic shock wave, similar to damped modes …
Pauli-Limited Effect In The Magnetic Phase Diagram Of Fesexte1−X Thin Films, Jincheng Zhuang, Zhen Li, Xun Xu, Li Wang, Wai Kong Yeoh, X Z. Xing, Zhixiang Shi, Xiaolin Wang, Yi Du, S X. Dou
Pauli-Limited Effect In The Magnetic Phase Diagram Of Fesexte1−X Thin Films, Jincheng Zhuang, Zhen Li, Xun Xu, Li Wang, Wai Kong Yeoh, X Z. Xing, Zhixiang Shi, Xiaolin Wang, Yi Du, S X. Dou
Australian Institute for Innovative Materials - Papers
We present a detailed investigation on the doping dependence of the upper critical fieldHc2(T) of FeSexTe1−xthin films (0.18 ≤ x ≤ 0.90) by measuring the electrical resistivity as a function of magnetic field. The Hc2(T) curves exhibit a downturn behavior with decreasing temperature in all the samples, owing to the Pauli-limited effect (spin paramagnetic effect). The Pauli-limited effect on the upper critical field can be monotonically modulated by variation of the Se/Te composition. Our results show that Te-doping induced disorder and excess Fe atoms give rise to enhancement of the Pauli-limited effect.
Mass Acquisition Of Dirac Fermions In Magnetically Doped Topological Insulator Sb2te3 Films, Yeping Jiang, Canli Song, Zhi Li, Mu Chen, Richard L. Greene, Ke He, Lili Wang, Xiaowei Chen, Xu-Cun Ma, Qi-Kun Xue
Mass Acquisition Of Dirac Fermions In Magnetically Doped Topological Insulator Sb2te3 Films, Yeping Jiang, Canli Song, Zhi Li, Mu Chen, Richard L. Greene, Ke He, Lili Wang, Xiaowei Chen, Xu-Cun Ma, Qi-Kun Xue
Australian Institute for Innovative Materials - Papers
We report on the mass acquisition of Dirac fermions by doping Cr into the topmost quintuple layer or into the bulk of Sb2Te3 topological insulator films. By careful investigation of the scanning tunneling microscopy/spectroscopy on the films, we find that the Landau level spectrum keeps a good quality even at a high Cr-doping level, enabling a demonstration of deviation of the zeroth Landau level, induced by the acquisition of a mass term in the surface states in the presence of surface or bulk magnetic doping. The magnitude of the mass term in the surface states increases with increasing Cr-doping level. …
Impacts Of Crystal Orientation Of Gaas On The Interfacial Structures And Electrical Properties Of Hf0.6la0.4ox Films, Tingting Jia, Hideo Kimura, Hongyang Zhao, Qiwen Yao, Zhenxiang Cheng, Xinghong Cheng, Yuehui Yu
Impacts Of Crystal Orientation Of Gaas On The Interfacial Structures And Electrical Properties Of Hf0.6la0.4ox Films, Tingting Jia, Hideo Kimura, Hongyang Zhao, Qiwen Yao, Zhenxiang Cheng, Xinghong Cheng, Yuehui Yu
Australian Institute for Innovative Materials - Papers
One of the major challenges in realizing the GaAs channel in the metal oxide semiconductor field effect transistor is the degrading in electron transport properties at the interface between GaAs and the gate oxide. In this study, Hf0.6La0.4Ox gate oxide films were deposited at a low temperature (200 °C) on GaAs(111)A and GaAs(100) substrates by plasma enhanced atomic layer deposition. Microstructure analysis indicates that residuals of gallium oxide, arsenic oxide, and As element remained at the interface of Hf0.6La0.4Ox/GaAs(100). On contrast, a smoother interface is observed between Hf0.6 …
Electronic Evidence Of An Insulator-Superconductor Crossover In Single-Layer Fese/Srtio3 Films, Junfeng He, Xu Liu, Wenhao Zhang, Lin Zhao, Defa Liu, Shaolong He, Daixiang Mou, Fangsen Li, Chenjia Tang, Zhi Li, Lili Wang, Yingying Peng, Yan Liu, Chaoyu Chen, Li Yu, Guodong Liu, Xiaoli Dong, Jun Zhang, Chuangtian Chen, Zuyan Xu, Xi Chen, Xu-Cun Ma, Qikun Xue, X J. Zhou
Electronic Evidence Of An Insulator-Superconductor Crossover In Single-Layer Fese/Srtio3 Films, Junfeng He, Xu Liu, Wenhao Zhang, Lin Zhao, Defa Liu, Shaolong He, Daixiang Mou, Fangsen Li, Chenjia Tang, Zhi Li, Lili Wang, Yingying Peng, Yan Liu, Chaoyu Chen, Li Yu, Guodong Liu, Xiaoli Dong, Jun Zhang, Chuangtian Chen, Zuyan Xu, Xi Chen, Xu-Cun Ma, Qikun Xue, X J. Zhou
Australian Institute for Innovative Materials - Papers
In high-temperature cuprate superconductors, it is now generally agreed that superconductivity is realized by doping an antiferromagnetic Mott (charge transfer) insulator. The doping-induced insulator-to-superconductor transition has been widely observed in cuprates, which provides important information for understanding the superconductivity mechanism. In the iron-based superconductors, however, the parent compound is mostly antiferromagnetic bad metal, raising a debate on whether an appropriate starting point should go with an itinerant picture or a localized picture. No evidence of doping-induced insulator-superconductor transition (or crossover) has been reported in the iron-based compounds so far. Here, we report an electronic evidence of an insulator-superconductor crossover observed …
Dichotomy Of The Electronic Structure And Superconductivity Between Single-Layer And Double-Layer Fese/Srtio3 Films, Xu Liu, Defa Liu, Wenchao Zhang, Junfeng He, Lin Zhao, Shaolong He, Daixiang Mou, Fangsen Li, Chenjia Tang, Zhi Li, Lili Wang, Yingying Peng, Yan Liu, Chaoyu Chen, Guodong Liu, Xiaoli Dong, Jun Zhang, Chuangtian Chen, Zuyan Xu, Xi Chen, Xu-Cun Ma, Qi-Kun Xue, X J. Zhou
Dichotomy Of The Electronic Structure And Superconductivity Between Single-Layer And Double-Layer Fese/Srtio3 Films, Xu Liu, Defa Liu, Wenchao Zhang, Junfeng He, Lin Zhao, Shaolong He, Daixiang Mou, Fangsen Li, Chenjia Tang, Zhi Li, Lili Wang, Yingying Peng, Yan Liu, Chaoyu Chen, Guodong Liu, Xiaoli Dong, Jun Zhang, Chuangtian Chen, Zuyan Xu, Xi Chen, Xu-Cun Ma, Qi-Kun Xue, X J. Zhou
Australian Institute for Innovative Materials - Papers
The latest discovery of possible high-temperature superconductivity in the single-layer FeSe film grown on a SrTiO3 substrate has generated much attention. Initial work found that, while the single-layer FeSe/SrTiO3 film exhibits a clear signature of superconductivity, the double-layer film shows an insulating behaviour. Such a marked layer-dependent difference is surprising and the underlying origin remains unclear. Here we report a comparative angleresolved photoemission study between the single-layer and double-layer FeSe/SrTiO3 films annealed in vacuum. We find that, different from the single-layer FeSe/SrTiO3 film, the double-layer FeSe/SrTiO3 film is hard to get doped and remains in the semiconducting/ insulating state under …
Direct Synthesis Of Rgo/Cu2o Composite Films On Cu Foil For Supercapacitors, Xiangmao Dong, Kun Wang, Chongjun Zhao, Xiuzhen Qian, Shi Chen, Zhen Li, Hua-Kun Liu, S X. Dou
Direct Synthesis Of Rgo/Cu2o Composite Films On Cu Foil For Supercapacitors, Xiangmao Dong, Kun Wang, Chongjun Zhao, Xiuzhen Qian, Shi Chen, Zhen Li, Hua-Kun Liu, S X. Dou
Australian Institute for Innovative Materials - Papers
Reduced graphene oxide/cuprous oxide (RGO/Cu2O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu2O and reduction of GO, in which Cu2O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu2O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry …
Optimization Of The Sequential Polymerization Synthesis Method For Polypyrrole Films, Danial Sangian, Wen Zheng, Geoffrey M. Spinks
Optimization Of The Sequential Polymerization Synthesis Method For Polypyrrole Films, Danial Sangian, Wen Zheng, Geoffrey M. Spinks
Australian Institute for Innovative Materials - Papers
Polypyrrole (PPy) is widely used as an electroactive material and is most often synthesized using electrochemical polymerization. Recently, a new electropolymerization method [1] was introduced that involved preparing the PPy as a sequential series of electrodeposited layers with solvent washing in between each deposited layer. This method enabled high quality PPy free-standing films to be prepared in a relatively short time. The purpose of the present study was to investigate the effect of the polymerization current density on the mechanical and electrical properties of the sequentially polymerized (SEP) PPy films. It was found that a low current density (0.1 mA/cm2) …
Photocatalytic Degradation Of Methyl Orange By Ceo2 And Fe-Doped Ceo2 Films Under Visible Light Irradiation, D Channei, B Inceesungvorn, N Wetchakun, S Ukritnukun, Andrew Nattestad, Jun Chen, S Phanichphant
Photocatalytic Degradation Of Methyl Orange By Ceo2 And Fe-Doped Ceo2 Films Under Visible Light Irradiation, D Channei, B Inceesungvorn, N Wetchakun, S Ukritnukun, Andrew Nattestad, Jun Chen, S Phanichphant
Australian Institute for Innovative Materials - Papers
Undoped CeO2 and 0.50-5.00 mol% Fe-doped CeO2 nanoparticles were prepared by a homogeneous precipitation combined with homogeneous/impreganation method, and applied as photocatalyst films prepared by a doctor blade technique. The superior photocatalytic performances of the Fe-doped CeO2 films, compared with undoped CeO2 films, was ascribed mainly to a decrease in band gap energy and an increase in specific surface area of the material. The presence of Fe3+ as found from XPS analysis, may act as electron acceptor and/or hole donor, facilitating longer lived charge carrier separation in Fe-doped CeO2 films as confirmed by photoluminescence spectroscopy. The 1.50 mol% Fe-doped CeO2 …
Enhanced Visible-Light Photocatalytic Activity Of G-C3n4/Tio2 Films, Natkritta Boonprakob, Natda Wetchakun, Sukon Phanichphant, David Wexler, Peter Sherrell, Andrew Nattestad, Jun Chen, Burapat Inceesungvorn
Enhanced Visible-Light Photocatalytic Activity Of G-C3n4/Tio2 Films, Natkritta Boonprakob, Natda Wetchakun, Sukon Phanichphant, David Wexler, Peter Sherrell, Andrew Nattestad, Jun Chen, Burapat Inceesungvorn
Australian Institute for Innovative Materials - Papers
Enhanced photocatalytic degradation of methylene blue (MB) using graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) catalyst films has been demonstrated in this present work. The g-C3N4/TiO2 composites were prepared by directly heating the mixture of melamine and pre-synthesized TiO2 nanoparticles in Ar gas flow. The g-C3N4 contents in the g-C3N4/TiO2 composites were varied as 0, 20, 50 and 70 wt%. It was found that the visible-light-induced photocatalytic degradation of MB was remarkably increased upon coupling TiO2 with g-C3N4 and the best degradation performance of ∼70% was obtained from 50 wt% g-C3N4 loading content. Results from UV–vis absorption study, Electron microscopy, Fourier transform …
Dispersion And Characterization Of Arc Discharge Single-Walled Carbon Nanotubes-Towards Conducting Transparent Films, Benedikt Rosner, Dirk Guldi, Jun Chen, Andrew Minett, Rainer H. Fink
Dispersion And Characterization Of Arc Discharge Single-Walled Carbon Nanotubes-Towards Conducting Transparent Films, Benedikt Rosner, Dirk Guldi, Jun Chen, Andrew Minett, Rainer H. Fink
Australian Institute for Innovative Materials - Papers
This study addresses a combination of a well-developed and mild dispersion method and high-quality arc discharge single-walled carbon nanotubes (SWCNTs) as starting materials. Thus, we advance in fabrication of transparent, conducting films with extraordinary low material loss during SWCNT processing. The starting material was characterized by means of thermogravimetric analysis, high-resolution transmission electron microscopy and Raman spectroscopy. The quality of the starting material and produced dispersions was evaluated by ultraviolet and visible light absorption spectroscopy and Raman spectroscopy. A transparent conductive film was fabricated by drop-casting, whereas films were obtained with electrical to optical conductivity ratios (σDC/σOp) as high as …
Thin, Tough, Ph-Sensitive Hydrogel Films With Rapid Load Recovery, Sina Naficy, Geoffrey M. Spinks, Gordon G. Wallace
Thin, Tough, Ph-Sensitive Hydrogel Films With Rapid Load Recovery, Sina Naficy, Geoffrey M. Spinks, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Stimuli-responsive hydrogels are used as the building blocks of actuators and sensors. Their application has been limited, however, by their lack of mechanical strength and recovery from loading. Here, we report the preparation of pH-sensitive hydrogels as thin as 20 μm. The hydrogels are made of a polyether-based polyurethane and poly(acrylic acid). A simple method was employed to create hydrogels with thicknesses in the range of 20-570 μm. The hydrogel films volume changed by a factor of ∼2 when the pH was switched around the transition point (pH 4). Tensile extensibilities of up to ∼350% were maintained at each pH, …
Fabrication Of Free-Standing Hierarchical Carbon Nanofiber/Graphene Oxide/Polyaniline Films For Supercapacitors, Dongdong Xu, Qun Xu, Kaixi Wang, Jun Chen, Zhimin Chen
Fabrication Of Free-Standing Hierarchical Carbon Nanofiber/Graphene Oxide/Polyaniline Films For Supercapacitors, Dongdong Xu, Qun Xu, Kaixi Wang, Jun Chen, Zhimin Chen
Australian Institute for Innovative Materials - Papers
A hierarchical high-performance electrode with nanoacanthine-style polyaniline (PANI) deposited onto a carbon nanofiber/graphene oxide (CNF/GO) template was successfully prepared via an in situ polymerization process. The morphology analysis shows that introducing one-dimensional (1D) CNF could significantly decrease/inhibit the staking of laminated GO to form an open-porous CNF/GO architecture. Followed with in situ facial deposition of PANI, the as-synthesized PANI modified CNF/GO exhibits three-dimensional (3D) hierarchical layered nanoarchitecture, which favors the diffusion of the electrolyte ions into the inner region of active materials. The hierarchical free-standing electrodes were directly fabricated into sandwich structured supercapacitors using 1 M H2SO4 as the electrolyte …
Pb Thin Films On Si(111): Local Density Of States And Defects, Stefan Eilers, Yi Du, S X. Dou
Pb Thin Films On Si(111): Local Density Of States And Defects, Stefan Eilers, Yi Du, S X. Dou
Australian Institute for Innovative Materials - Papers
Local density of states and atomic structure of the stripped incommensurate phase, the √3 x√7 phase and the 1 x 1 phase of a monolayer of Pb on Si(111) are characterized by scanning tunneling microscopy and spectroscopy. The dI/dV-images reveal congruent local density of states structures for the stripped incommensurate and the √3 x√ phase but suggest a hexagonal lattice of the local density of states for the 1x1 phase while the atomic structure consists of one more atom in the center of each hexagon. Vacancy defects and impurities show a depletion of local density of states for the stripped …
Interface Charge Doping Effects On Superconductivity Of Single-Unit-Cell Fese Films On Srtio3 Substrates, Wenhao Zhang, Zhi Li, Fangsen Li, Huimin Zhang, Jun-Ping Peng, Chenjia Tang, Qingyan Wang, Ke He, Xi Chen, Lili Wang, Xu-Cun Ma, Qi-Kun Xue
Interface Charge Doping Effects On Superconductivity Of Single-Unit-Cell Fese Films On Srtio3 Substrates, Wenhao Zhang, Zhi Li, Fangsen Li, Huimin Zhang, Jun-Ping Peng, Chenjia Tang, Qingyan Wang, Ke He, Xi Chen, Lili Wang, Xu-Cun Ma, Qi-Kun Xue
Australian Institute for Innovative Materials - Papers
We prepare single-unit-cell FeSe films on insulating SrTiO3 substrates by molecular beam epitaxy and investigate the evolution of their superconducting properties with annealing by in situ scanning tunneling microscopy and scanning tunneling spectroscopy and ex situ transport measurements. We find that through an annealing process, the superconductivity of 1-uc FeSe films on SrTiO3 substrates develops with the formation of stoichiometric FeSe films and is further enhanced by charge transfer from SrTiO3 substrates to FeSe films. Moreover, the superconductivity is independent of the bulk property of the SrTiO3 substrate, regardless of whether it is insulating or conductive. Our results reveal that …
Imaging The Electron-Boson Coupling In Superconducting Fese Films Using A Scanning Tunneling Microscope, Canli Song, Yi-Lin Wang, Yeping Jiang, Zhi Li, Lili Wang, Ke He, Xi Chen, Jennifer E. Hoffman, Xu-Cun Ma, Qi-Kun Xue
Imaging The Electron-Boson Coupling In Superconducting Fese Films Using A Scanning Tunneling Microscope, Canli Song, Yi-Lin Wang, Yeping Jiang, Zhi Li, Lili Wang, Ke He, Xi Chen, Jennifer E. Hoffman, Xu-Cun Ma, Qi-Kun Xue
Australian Institute for Innovative Materials - Papers
Scanning tunneling spectroscopy has been used to reveal signatures of a bosonic mode in the local quasiparticle density of states of superconducting FeSe films. The mode appears below Tc as a "dip-hump" feature at energy Ω ∼ 4.7kBTc beyond the superconducting gap Δ. Spectra on strained regions of the FeSe films reveal simultaneous decreases in Δ and Ω. This contrasts with all previous reports on other high-Tc superconductors, where Δ locally anticorrelates with Ω. A local strong coupling model is found to reconcile the discrepancy well, and to provide a unified picture of the electron-boson coupling in unconventional superconductors.