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Articles 1 - 30 of 109
Full-Text Articles in Physical Sciences and Mathematics
Room Temperature Giant And Linear Magnetoresistance In Topological Insulator Bi2te3 Nanosheets, Xiaolin Wang, Yi Du, S X. Dou, Chao Zang
Room Temperature Giant And Linear Magnetoresistance In Topological Insulator Bi2te3 Nanosheets, Xiaolin Wang, Yi Du, S X. Dou, Chao Zang
Shi Xue Dou
"Topological insulators, a new class of condensed matter having bulk insulating states and gapless metallic surface states, have demonstrated fascinating quantum effects. However, the potential practical applications of the topological insulators are still under exploration worldwide. We demonstrate that nanosheets of a Bi2Te3 topological insulator several quintuple layers thick display giant and linear magnetoresistance. The giant and linear magnetoresistance achieved is as high as over 600% at room temperature, with a trend towards further increase at higher temperatures, as well as being weakly temperature-dependent and linear with the field, without any sign of saturation at measured fields up to 13 …
High Performance Pure Sulfur Honeycomb-Like Architectures Synthesized By A Cooperative Self-Assembly Strategy For Lithium Sulfur Batteries, Xin Liang, Mohammad Kaiser, Konstantin Konstantinov, Richard Tandiono, Zhaoxiang Prof Zhaoxiang Wang, Hua-Kun Liu, S X. Dou, Jiazhao Wang
High Performance Pure Sulfur Honeycomb-Like Architectures Synthesized By A Cooperative Self-Assembly Strategy For Lithium Sulfur Batteries, Xin Liang, Mohammad Kaiser, Konstantin Konstantinov, Richard Tandiono, Zhaoxiang Prof Zhaoxiang Wang, Hua-Kun Liu, S X. Dou, Jiazhao Wang
Shi Xue Dou
Honeycomb-like pure sulfur architectures were synthesized by a cooperative self-assembly strategy, in which a soft template is used to form the porous structure. Their electrochemical performance is significantly improved comparing with the commercial sulfur powder and the as-prepared sulfur without honeycomb morphology. There has been no report on using a soft template to prepare honeycomb-like sulfur particles.
Enhancement Of Transition Temperature In Fexse0.5te0.5 Film Via Iron Vacancies, J C. Zhuang, Wai K. Yeoh, Xiangyuan Cui, Jung Ho Kim, Dongqi Shi, Z X. Shi, S P. Ringer, Xiaolin Wang, S X. Dou
Enhancement Of Transition Temperature In Fexse0.5te0.5 Film Via Iron Vacancies, J C. Zhuang, Wai K. Yeoh, Xiangyuan Cui, Jung Ho Kim, Dongqi Shi, Z X. Shi, S P. Ringer, Xiaolin Wang, S X. Dou
Shi Xue Dou
The effects of iron deficiency in Fe x Se0.5Te0.5 thin films (0.8 ≤ x ≤ 1) on superconductivity and electronic properties have been studied. A significant enhancement of the superconducting transition temperature (TC ) up to 21 K was observed in the most Fe deficient film (x = 0.8). Based on the observed and simulated structural variation results, there is a high possibility that Fe vacancies can be formed in the Fe x Se0.5Te0.5 films. The enhancement of TC shows a strong relationship with the lattice strain effect induced by Fe vacancies. Importantly, the presence of Fe vacancies alters the …
Power-Law Relationship Between Critical Current Density, Microstructure, And The N-Value In Mgb2 Superconductor Wires, Ashkan Motaman, Shaon Barua, Dipak Patel, Minoru Maeda, Kookchae Cheong, Jung Ho Kim, S X. Dou, Md Shahriar Al Hossain
Power-Law Relationship Between Critical Current Density, Microstructure, And The N-Value In Mgb2 Superconductor Wires, Ashkan Motaman, Shaon Barua, Dipak Patel, Minoru Maeda, Kookchae Cheong, Jung Ho Kim, S X. Dou, Md Shahriar Al Hossain
Shi Xue Dou
Dissipation-free MgB2 superconducting wires are valuable in terms of practical applications. Herein, we have found a strong correlation between critical current density (J c ) and the n-value extracted from the electric field versus current density characteristic. The power-law relationship (m) between the J c and the n-value, n∝Jmc , represents a critical index which is strongly dependent on operating temperatures.
Pressure Induced Magneto-Structural Phase Transitions In Layered Rmn2x2 Compounds (Invited), Shane Kennedy, Jianli Wang, Stewart Campbell, Michael Hofmann, S X. Dou
Pressure Induced Magneto-Structural Phase Transitions In Layered Rmn2x2 Compounds (Invited), Shane Kennedy, Jianli Wang, Stewart Campbell, Michael Hofmann, S X. Dou
Shi Xue Dou
We have studied a range of pseudo-ternaries derived from the parent compound PrMn2 Ge 2, substituting for each constituent element with a smaller one to contract the lattice. This enables us to observe the magneto-elastic transitions that occur as the Mn-Mn nearest neighbour distance is reduced and to assess the role of Pr on the magnetism. Here, we report on the PrMn2 Ge 2−xSix, Pr1−xYxMn2 Ge 2, and PrMn2−xFex Ge 2 systems. The pressure produced by chemical substitution in these pseudo-ternaries is inherently non-uniform, with local pressure variations dependent on the local atomic distribution. We find that concentrated chemical substitution …
Ultra-Small Fluorescent Inorganic Nanoparticles For Bioimaging, Zhen Li, Qiao Sun, Yian Zhu, Bien Tan, Zhi Ping Xu, S X. Dou
Ultra-Small Fluorescent Inorganic Nanoparticles For Bioimaging, Zhen Li, Qiao Sun, Yian Zhu, Bien Tan, Zhi Ping Xu, S X. Dou
Shi Xue Dou
The novel optical, electrical, and magnetic properties of ultra-small inorganic nanoparticles make them very attractive in diverse applications in the fields of health, clean and renewable energy, and environmental sustainability. This article comprehensively summarizes state-of-the-art fluorescence imaging using ultra-small nanoparticles as probes, including quantum dots, metal nanoclusters, carbon nanomaterials, up-conversion, and silicon nanomaterials.
Thermoelectric Performance Of N-Type (Pbte)0.75(Pbs)0.15(Pbse)0.1 Composites, Sima Aminorroaya Yamini, Heng Wang, Dianta Ginting, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Thermoelectric Performance Of N-Type (Pbte)0.75(Pbs)0.15(Pbse)0.1 Composites, Sima Aminorroaya Yamini, Heng Wang, Dianta Ginting, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Shi Xue Dou
Lead chalcogenides (PbQ, Q = Te, Se, S) have proved to possess high thermoelectric efficiency for both n-type and p-type compounds. Recent success in tuning of electronic band structure, including manipulating the band gap, multiple bands, or introducing resonant states, has led to a significant improvement in the thermoelectric performance of p-type lead chalcogenides compared to the n-type ones. Here, the n-type quaternary composites of (PbTe)0.75(PbS)0.15(PbSe)0.1 are studied to evaluate the effects of nanostructuring on lattice thermal conductivity, carrier mobility, and effective mass variation. The results are compared with the similar ternary systems of (PbTe)1-x(PbSe)x, (PbSe) 1-x(PbS)x, and (PbS)1-x(PbTe)x. The …
Magnetic Transitions In Lafe13-X-Ycoysix Compounds, Jianli Wang, S J. Campbell, S J. Kennedy, P Shamba, R Zeng, S X. Dou, G H. Wu
Magnetic Transitions In Lafe13-X-Ycoysix Compounds, Jianli Wang, S J. Campbell, S J. Kennedy, P Shamba, R Zeng, S X. Dou, G H. Wu
Shi Xue Dou
The magnetic properties of a set of LaFe13−x−yCoySix compounds (x = 1.6 − 2.6; y = 0, y = 1.0) have been investigated using magnetic measurements, thermal expansion, 57Fe Mössbauer spectroscopy and high resolution neutron powder diffraction methods over the temperature range 10–300 K. The natures of the magnetic transitions in these LaFe13−x−yCoySix compounds have been determined. The Curie temperatures of LaFe13−xSix were found to increase with Si content from TC = 219(5) K for Si content x = 1.6 to TC = 250(5) K for x = 2.6. Substitution of Co for Fe in LaFe10.4Si2.6 resulted in a further …
Thermoelectric Performance Of Tellurium-Reduced Quaternary P-Type Lead-Chalcogenide Composites, Sima Aminorroaya Yamini, Heng Wang, Zachary M. Gibbs, Yanzhong Pei, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Thermoelectric Performance Of Tellurium-Reduced Quaternary P-Type Lead-Chalcogenide Composites, Sima Aminorroaya Yamini, Heng Wang, Zachary M. Gibbs, Yanzhong Pei, David R. G Mitchell, S X. Dou, G. Jeffrey Snyder
Shi Xue Dou
A long-standing technological challenge to the widespread application of thermoelectric generators is obtaining high-performance thermoelectric materials from abundant elements. Intensive study on PbTe alloys has resulted in a high figure of merit for the single-phase ternary PbTe-PbSe system through band structure engineering, and the low thermal conductivity achieved due to nanostructuring leads to high thermoelectric performance for ternary PbTe-PbS compounds. Recently, the single-phase p-type quaternary PbTe-PbSe-PbS alloys have been shown to provide thermoelectric performance superior to the binary and ternary lead chalcogenides. This occurs via tuning of the band structure and from an extraordinary low thermal conductivity resulting from high-contrast …
Platinum Dendritic Nanoparticles With Magnetic Behavior, Wenxian Li, Ziqi Sun, Dongliang Tian, Ivan P. Nevirkovets, S X. Dou
Platinum Dendritic Nanoparticles With Magnetic Behavior, Wenxian Li, Ziqi Sun, Dongliang Tian, Ivan P. Nevirkovets, S X. Dou
Shi Xue Dou
Magnetic nanoparticles have attracted increasing attention for biomedical applications in magnetic resonance imaging, high frequency magnetic field hyperthermia therapies, and magnetic-field-gradient-targeted drug delivery. In this study, three-dimensional (3D) platinum nanostructures with large surface area that features magnetic behavior have been demonstrated. The well-developed 3D nanodendrites consist of plentiful interconnected nano-arms ∼4 nm in size. The magnetic behavior of the 3D dendritic Pt nanoparticles is contributed by the localization of surface electrons due to strongly bonded oxygen/Pluronic F127 and the local magnetic moment induced by oxygen vacancies on the neighboring Pt and O atoms. The magnetization of the nanoparticles exhibits a …
Recent Progress In Thermoelectric Materials, Chao Han, Zhen Li, S X. Dou
Recent Progress In Thermoelectric Materials, Chao Han, Zhen Li, S X. Dou
Shi Xue Dou
Direct conversion of heat into electricity through advanced thermoelectric (TE) materials has been one of the most attractive solutions to the severe environmental and energy issues facing humanity. In recent years, great progress has been made in improving their dimensionless figure of merit (ZT), which determines the conversion efficiency of TE devices. ZT is related to three “interlocked” factors—the Seebeck coefficient, electrical conductivity, and thermal conductivity. These three factors are interdependent in bulk TE materials, and altering one changes the other two. The difficulty in simultaneously optimizing them caused TE research to stagnate, until great reductions in thermal conductivity were …
Large Magnetoelectric Coupling In Magnetically Short-Range Ordered Bi5ti3feo15 Film, Hongyang Zhao, Hideo Kimura, Zhenxiang Cheng, Minoru Osada, Jianli Wang, Xiaolin Wang, S X. Dou, Yan Liu, Jianding Yu, Takao Matsumoto, Tetsuya Tohei, Naoya Shibata, Yuichi Ikuhara
Large Magnetoelectric Coupling In Magnetically Short-Range Ordered Bi5ti3feo15 Film, Hongyang Zhao, Hideo Kimura, Zhenxiang Cheng, Minoru Osada, Jianli Wang, Xiaolin Wang, S X. Dou, Yan Liu, Jianding Yu, Takao Matsumoto, Tetsuya Tohei, Naoya Shibata, Yuichi Ikuhara
Shi Xue Dou
Multiferroic materials, which offer the possibility of manipulating the magnetic state by an electric field or vice versa, are of great current interest. However, single-phase materials with such cross-coupling properties at room temperature exist rarely in nature; new design of nano-engineered thin films with a strong magneto-electric coupling is a fundamental challenge. Here we demonstrate a robust room-temperature magneto-electric coupling in a bismuth-layer-structured ferroelectric Bi5Ti3FeO15 with high ferroelectric Curie temperature of ~1000 K. Bi5Ti3FeO15 thin films grown by pulsed laser deposition are single-phase layered perovskit with nearly (00l)-orientation. Room-temperature multiferroic behavior is demonstrated by a large modulation in magneto-polarization and …
High-Performance Sodium-Ion Batteries And Sodium-Ion Pseudocapacitors Based On Mos2/Graphene Composites, Yunxiao Wang, Shulei Chou, David Wexler, Hua-Kun Liu, S X. Dou
High-Performance Sodium-Ion Batteries And Sodium-Ion Pseudocapacitors Based On Mos2/Graphene Composites, Yunxiao Wang, Shulei Chou, David Wexler, Hua-Kun Liu, S X. Dou
Shi Xue Dou
Sodium-ion energy storage, including sodium-ion batteries (NIBs) and electrochemical capacitive storage (NICs), is considered as a promising alternative to lithium-ion energy storage. It is an intriguing prospect, especially for large-scale applications, owing to its low cost and abundance. MoS2 sodiation/desodiation with Na ions is based on the conversion reaction, which is not only able to deliver higher capacity than the intercalation reaction, but can also be applied in capacitive storage owing to its typically sloping charge/discharge curves. Here, NIBs and NICs based on a graphene composite (MoS2/G) were constructed. The enlarged d-spacing, a contribution of the graphene matrix, and the …
Magnetic Properties And Magnetocaloric Effect Of Ndmn2-Xcuxsi2 Compounds, M F. Md Din, Jianli Wang, M Avdeev, Q F. Gu, R Zeng, S J. Campbell, S J. Kennedy, S X. Dou
Magnetic Properties And Magnetocaloric Effect Of Ndmn2-Xcuxsi2 Compounds, M F. Md Din, Jianli Wang, M Avdeev, Q F. Gu, R Zeng, S J. Campbell, S J. Kennedy, S X. Dou
Shi Xue Dou
Structural and magnetic properties of NdMn2−x Cu xSi2 compounds (x = 0-1.0) have been investigated by high intensity x-ray and resolution neutron diffraction (3-450 K), specific heat, dc magnetization, and differential scanning calorimetry measurements. Substitution of Cu for Mn leads to an increase in the lattice parameter a but a decrease in c at room temperature. Two magnetic phase transitions have been found for NdMn2−x Cu xSi2 compounds with TN for the antiferromagnetic ordering of Mn-sublatttice and TC for the Nd-sublattice ferromagnetic ordering, respectively. TC increases significantly with increasing Cu content from 36 K at x = 0 to 100 …
Exchange Interaction Mediated Ferroelectricity In Multiferroic Mntio3 With Anisotropic Orbital Hybridization And Hole Delocalization, Shiwei Chen, Paoan Lin, Horngtay Jeng, S W. Fu, Jennmin Lee, Jyhfu Lee, Chihwen Pao, Hirofumi Ishii, Kuding Tsuei, Nozomu Hiraoka, Dapeng Chen, S X. Dou, Xiaolin Wang, Kueihtzu Lu, Jinming Chen
Exchange Interaction Mediated Ferroelectricity In Multiferroic Mntio3 With Anisotropic Orbital Hybridization And Hole Delocalization, Shiwei Chen, Paoan Lin, Horngtay Jeng, S W. Fu, Jennmin Lee, Jyhfu Lee, Chihwen Pao, Hirofumi Ishii, Kuding Tsuei, Nozomu Hiraoka, Dapeng Chen, S X. Dou, Xiaolin Wang, Kueihtzu Lu, Jinming Chen
Shi Xue Dou
We present the orbital structure of MnTiO3 with polarization dependent x-ray absorption and resonant x-ray emission spectra accompanied with electronic structure calculations. The results clearly indicate a strongly anisotropic O 2p-Mn 3d orbital hybridization whereas the Mn 3d hole state shows a highly delocalized characteristic ascribed to the 3d-4p mixing. The extended Mn 4p orbital could enhance the exchange interaction between Mn (3d)-O (2p)-Mn (3d) leading to an asymmetric charge distribution in Mn-O bonds. The delocalized characteristic of Mn 3d holes is indispensable to the mechanism of spin-dependent-metal-ligand hybridization to explain magnetically induced ferroelectricity.
Ultra-High Performance, High-Temperature Superconducting Wires Via Cost-Effective, Scalable, Co-Evaporation Process, Ho-Sup Kim, Sang-Soo Oh, Hong-Soo Ha, Dojun Youm, Seung-Hyun Moon, Jung Ho Kim, S X. Dou, Yoon-Uk Heo, Sung-Hun Wee, Amit Goyal
Ultra-High Performance, High-Temperature Superconducting Wires Via Cost-Effective, Scalable, Co-Evaporation Process, Ho-Sup Kim, Sang-Soo Oh, Hong-Soo Ha, Dojun Youm, Seung-Hyun Moon, Jung Ho Kim, S X. Dou, Yoon-Uk Heo, Sung-Hun Wee, Amit Goyal
Shi Xue Dou
Long-length, high-temperature superconducting (HTS) wires capable of carrying high critical current, Ic, are required for a wide range of applications. Here, we report extremely high performance HTS wires based on 5 μm thick SmBa2Cu3O7 − δ (SmBCO) single layer films on textured metallic templates. SmBCO layer wires over 20 meters long were deposited by a cost-effective, scalable co-evaporation process using a batch-type drum in a dual chamber. All deposition parameters influencing the composition, phase, and texture of the films were optimized via a unique combinatorial method that is broadly applicable for co-evaporation of other promising complex materials containing several cations. …
Interface Strain-Induced Multiferroicity In A Smfeo3 Film, Zhenxiang Cheng, Fang Hong, Yuanxu Wang, Kiyoshi Ozawa, Hiroki Fujii, Hideo Kimura, Yi Du, Xiaolin Wang, S X. Dou
Interface Strain-Induced Multiferroicity In A Smfeo3 Film, Zhenxiang Cheng, Fang Hong, Yuanxu Wang, Kiyoshi Ozawa, Hiroki Fujii, Hideo Kimura, Yi Du, Xiaolin Wang, S X. Dou
Shi Xue Dou
An epitaxial pseudocubic SmFeO3 thin film on (100) Nb-SrTiO 3 was studied based on ferroelectric (FE) characterization and magnetic measurements. High-resolution transmission electron microscopy images clarify the nature of the epitaxial growth, the stress-induced structural distortion at the film/substrate interface, and the existence of two different orientation lattices. Clear grain boundaries can be seen, which could introduce an extra local distortion. Rectangular FE loops can be observed at room temperature, even by just applying a small voltage ranging from -1 to +1 V, indicative of the presence of FE polarization. Piezoelectric force microscopy images confirm the existence of FE domains …
A Comparative Study Of Magnetic Behaviors In Tbni2, Tbmn2 And Tbni2mn, Jianli Wang, M F. Md Din, Shane Kennedy, F Hong, Stewart J. Campbell, A J. Studer, G H. Wu, Zhenxiang Cheng, S X. Dou
A Comparative Study Of Magnetic Behaviors In Tbni2, Tbmn2 And Tbni2mn, Jianli Wang, M F. Md Din, Shane Kennedy, F Hong, Stewart J. Campbell, A J. Studer, G H. Wu, Zhenxiang Cheng, S X. Dou
Shi Xue Dou
All TbNi2, TbMn2, and TbNi2Mn compounds exhibit the cubic Laves phase with AB2-type structure in spite of the fact that the ratio of the Tb to transition-metal components in TbNi2Mn is 1:3. Rietveld refinement indicates that in TbNi2Mn the Mn atoms are distributed on both the A (8a) and B (16d) sites. The values of the lattice constants were measured to be a = 14.348 Å (space group F-43 m), 7.618 Å, and 7.158 Å (space group Fd-3 m) for TbNi2, TbMn2, and TbNi2Mn, respectively. The magnetic transition temperatures TC were found to be TC = 38 K and TC …
One-Pot Aqueous Synthesis Of Cysteine-Capped Cdte/Cds Core-Shell Nanowires, Yukai Shan, Zhen Xiao, Yongming Chuan, Hongli Li, Minglong Yuan, Zhen Li, S X. Dou
One-Pot Aqueous Synthesis Of Cysteine-Capped Cdte/Cds Core-Shell Nanowires, Yukai Shan, Zhen Xiao, Yongming Chuan, Hongli Li, Minglong Yuan, Zhen Li, S X. Dou
Shi Xue Dou
Highly fluorescent cysteine-capped CdTe/CdS core-shell nanowires were successfully synthesized by reacting CdCl2 with NaHTe in aqueous solution under refluxing at 100 °C for 140 min. On increasing the reaction time from 10 to 140 min, CdTe/CdS nanocrystals gradually grew into nanorods and eventually completely evolved into nanowires. The nanowires have amino and carboxyl functional groups on their surfaces and can be well dispersed in aqueous solution. The as-prepared CdTe/CdS nanowires show a fluorescence quantum yield (QY) of 7.25 % due to the unique nature of cysteine and the formation of a CdS shell on the surface of the CdTe core, …
Giant Interlayer Magnetoresistances And Strong Anisotropy In P-Type Sb2te3 Single Crystals, Zengji Yue, Xiaolin Wang, S X. Dou
Giant Interlayer Magnetoresistances And Strong Anisotropy In P-Type Sb2te3 Single Crystals, Zengji Yue, Xiaolin Wang, S X. Dou
Shi Xue Dou
Anisotropic interlayer magneto-transport properties have been studied over a broad range of temperatures and magnetic fields in p-type Sb2Te3 single crystals. Giant interlayer magnetoresistance (MR) of up to 400% was observed, which exhibits quadratic field dependences in low fields and becomes linear at high fields without any trend towards saturation. The interlayer MR displays strong anisotropy and is attributable to the anisotropy of the Fermi surface. The observed giant anisotropic interlayer MR could find applications in p-type Sb2Te3 based magneto-electronic devices.
Positive And Negative Exchange Bias Effects In The Simple Perovskite Manganite Ndmno3, Fang Hong, Zhenxiang Cheng, Jianli Wang, Xiaolin Wang, S X. Dou
Positive And Negative Exchange Bias Effects In The Simple Perovskite Manganite Ndmno3, Fang Hong, Zhenxiang Cheng, Jianli Wang, Xiaolin Wang, S X. Dou
Shi Xue Dou
Exchange bias effects were studied in the simple perovskite NdMnO 3. Nd 3+ ordering is induced by the Mn 3+ ferromagnetic component, and they are antiferromagnetically coupled with each other. At 30 K, both negative and positive exchange bias effects are found, which are dependent on the cooling field. The exchange bias fields are around -2400 Oe and 1800 Oe, respectively. Positive and negative exchange bias effects were also observed at 8 K, but the exchange bias fields are only 130 Oe and -120 Oe. The coupling intensity between Nd 3+ ordering and Mn 3+ ordering, and their initial states …
Nanocomposites Of Silicon And Carbon Derived From Coal Tar Pitch: Cheap Anode Materials For Lithium-Ion Batteries With Long Cycle Life And Enhanced Capacity, Yun-Xiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Nanocomposites Of Silicon And Carbon Derived From Coal Tar Pitch: Cheap Anode Materials For Lithium-Ion Batteries With Long Cycle Life And Enhanced Capacity, Yun-Xiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
From energy and environmental consideration, an industrial waste product, coal tar pitch (CTP), is used as the carbon source for Si/AC composite. We exploited a facile sintering method to largely scale up Si/amorphous carbon nanocomposite. The composites with 20 wt.% silicon with PVdF binder exhibited stable lithium storage ability for prolonged cycling. The composite anode delivered a capacity of 400.3 mAh g−1 with a high capacity retention of 71.3% after 1000 cycles. Various methods are used to investigate the reason for the outstanding cyclability. The results indicate that the silicon nanoparticles are wrapped by amorphous SiOx and AC in Si/AC …
Magnetotransport Dependence On The Field Magnitude And Direction In Large Area Epitaxial Graphene Film On Stretchable Substrates, Peite Bao, Wenxian Li, Wai Kong Yeoh, Xiangyuan Cui, J. H. Kim, Yong-Mook Kang, Wenrong Yang, S X. Dou, Simon P. Ringer, Rongkun Zheng
Magnetotransport Dependence On The Field Magnitude And Direction In Large Area Epitaxial Graphene Film On Stretchable Substrates, Peite Bao, Wenxian Li, Wai Kong Yeoh, Xiangyuan Cui, J. H. Kim, Yong-Mook Kang, Wenrong Yang, S X. Dou, Simon P. Ringer, Rongkun Zheng
Shi Xue Dou
We report the magnetotransport properties of large area graphene on stretchable polyethylene terephthalate substrates. At 2 K, weak localization of electrons introduced negative magnetoresistance at low field; a transition to positive magnetoresistance followed as the external field increases. Our results suggest that weak localization contributes to Hall effect at low temperature. At room temperature, only classical Lorentz force contribution can be observed. Angular dependence of the external magnetic field on longitudinal and transverse resistivity is measured to test the interplay between weak localization and Lorentz force contribution. Quantitative simulations based on quantum interference theory produced excellent agreement with the experiments.
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
Shi Xue Dou
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 temperatures (about 950 °C) in HPS MGB2 does not …
Reduced Graphene Oxide With Superior Cycling Stability And Rate Capability For Sodium Storage, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Reduced Graphene Oxide With Superior Cycling Stability And Rate Capability For Sodium Storage, Yunxiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
Sodium ion battery is a promising electrical energy storage system for sustainable energy storage applications due to the abundance of sodium resources and their low cost. In this communication, the electrochemical properties of sodium ion storage in reduced graphene oxide (RGO) were studied in an electrolyte consisting of 1 M NaClO4 in propylene carbonate (PC). The experimental results show that the RGO anode allowed significant sodium ion insertion, leading to higher capacity at high current density compared to the previously reported results for carbon materials. This is due to the fact that RGO possesses higher electrical conductivity and is a …
A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou
A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou
Shi Xue Dou
Transition metal oxide (Mn3O4, Fe2O3, Co3O4, and ZnO) and reduced graphene oxide (RGO) composites were successfully synthesized via a hydrothermal method using the direct reaction between the corresponding metal powder and graphene oxide (GO). In this process, the GO can be reduced by transition metal powder in water, and the nanosized metal oxide can be obtained, and homogeneously mixed with and wrapped by RGO to form a metal oxide/RGO composite at the same time. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy were used to characterize the as-prepared materials. The different experimental parameters, including reactants, …
Magnetic Properties And Magnetocaloric Effect Of Ndmn2−Xtixsi2 Compounds, M F. Md Din, Jianli Wang, S J. Campbell, R Zeng, W D. Hutchison, M Avdeev, S J. Kennedy, S X. Dou
Magnetic Properties And Magnetocaloric Effect Of Ndmn2−Xtixsi2 Compounds, M F. Md Din, Jianli Wang, S J. Campbell, R Zeng, W D. Hutchison, M Avdeev, S J. Kennedy, S X. Dou
Shi Xue Dou
The structural and magnetic properties of the intermetallic compounds NdMn2−xTixSi2(x = 0, 0.1, 0.2, and 0.3) have been studied by x-ray and high resolution neutron powder diffraction, specific heat, dc magnetization, and differential scanning calorimetry measurements over the temperature range 3–450 K. The Curie temperature and Néel temperature of NdMn2Si2 decrease from TC = 36 K and TN = 380 K to TC = 14 K and TN = 360 K, respectively, on substitution of Ti (x = 0.3) for Mn. The magnetocaloric effect at the first order ferromagnetic phase transition at TC, has been investigated in detail. Under a …
Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou
Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou
Shi Xue Dou
The flux pinning mechanism of BaFe1.9Ni0.1As2 superconducting crystals have been investigated systematically by magnetic measurements up to 13 T at various temperatures. The field dependence of the critical current density, Jc, was analysed within the collective pinning model. A remarkably good agreement between the experimental results and theoretical dl pinning curve is obtained, which indicates that pinning in BaFe1.9Ni0.1As2 crystal originates from spatial variation of the mean free path. Moreover, the normalized pinning force density, Fp, curves versus h1/4B/Birr (Birr is the irreversibility field) were scaled using the Dew-Hughes model. Analysis suggests that point pinning alone cannot explain the observed …
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
Shi Xue Dou
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 …
Driving Magnetostructural Transitions In Layered Intermetallic Compounds, Jianli Wang, L Caron, S J. Campbell, S J. Kennedy, M Hofmann, Z X Cheng, M Md Din, A J. Studer, E Bruck, S X. Dou
Driving Magnetostructural Transitions In Layered Intermetallic Compounds, Jianli Wang, L Caron, S J. Campbell, S J. Kennedy, M Hofmann, Z X Cheng, M Md Din, A J. Studer, E Bruck, S X. Dou
Shi Xue Dou
We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr0.5Y0.5Mn 2Ge2. In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (TCPr). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase …