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Full-Text Articles in Physical Sciences and Mathematics
Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace
Capacitive Behavior Of Latex/Single-Wall Carbon Nanotube Stretchable Electrodes, Hyeon Taek Jeong, Byung Kim, Robert Gorkin Iii, Michael J. Higgins, Gordon G. Wallace
Robert Gorkin III
In this report single-wall carbon nanotubes (SWNTs) were coated onto latex using spray coating to produce a stretchable electrode. The electrochemical properties of the electrode were determined using cyclic voltammetry and electrochemical impedance spectroscopy and galvanostatic charge/discharge tests were also carried out. The impedance and charge/discharge curves of the latex/SWNTs electrode showed good capacitive behavior even after repetitive stretching to 100% strain. The highest capacitance value obtained for the unstretched SWNTs electrode was 119 F g−1 in 1 M Na2SO4 at 5 mV s−1. After the 100th stretch ≈ 80% of the original capacitance value was retained.
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.
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 …
The Flux Pinning Mechanism, And Electrical And Magnetic Anisotropy In Fe1.04te0.6se0.4 Superconducting Single Crystal, Mahboobeh Shahbazi-Manshadi, Xiaolin Wang, S X. Dou, H Fang, C T. Lin
The Flux Pinning Mechanism, And Electrical And Magnetic Anisotropy In Fe1.04te0.6se0.4 Superconducting Single Crystal, Mahboobeh Shahbazi-Manshadi, Xiaolin Wang, S X. Dou, H Fang, C T. Lin
Shi Xue Dou
The temperature and magnetic field dependences of the magnetization and critical current density of Fe1.04Te0.6Se0.4 single crystals have been investigated, and the flux pinning mechanism has been analysed. The normalized pinning force (fp Fp/F p,max) vs. h(H/Hirr) curves, are scaled using the Dew-Hughes theory, f(h) ≈ hp(1 - h)q with p 1.35 and q 3.06. The angular dependence of the resistivity under different magnetic fields shows a dip-like structure, below the superconducting transition temperature. The anisotropic value of 2 was obtained using Ginzburg-Landau theory.
Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou
Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou
Jianli Wang
YFeO3 single crystal displays two relaxor-like dielectric relaxations, one at low temperature (170300 K) and one at high temperature (370520 K), which are attributed to the activation of electrons and oxygen vacancies, respectively. Above the temperature at which electrons are activated, the sample displays a large magnetocapacitance effect. Comparison of the impedance Cole-Cole plots measured with and without applied magnetic field reveals that the occurrence of magnetocapacitance effect is accompanied with an increasing in DC conductivity under magnetic field after the activation of electrons, which is explained by the enhancement of electron jumping in Fe2b-O-Fe3b chains by magnetic field. Thus …
Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou
Anisotropic And Excellent Magnetocaloric Properties Of La 0.7ca0.3mno3 Single Crystal With Anomalous Magnetization, J.C Debnath, Rong Zeng, Jung Ho Kim, Dapeng Chen, S X. Dou
Shi Xue Dou
Magnetic properties and the magnetocaloric effect (MCE) have been investigated in La0.7Ca0.3MnO3 single crystal with applied field along both the ab-plane and the c-direction. Due to the magnetocrystalline anisotropy, the crystal exhibits anisotropy in the MCE. Upon application of a 5 T field, the magnetic entropy changes (SM), reaching values of 7.668 J/(kg K) and 6.412 J/(kg K) for both the ab-plane and the c-direction, respectively. A magnetic entropy change of 3.3 J/(kg K) was achieved for a magnetic field change of 1.5 T at the Curie temperature, TC = 245 K. Due to the absence of grains in the …
Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou
Effect Of Frozen Spin On The Magnetocaloric Property Of La0.7ca0.3coo3 Polycrystalline And Single Crystal Samples, J C. Debnath, R Zeng, J H. Kim, P Shamba, Dapeng Chen, S X. Dou
Shi Xue Dou
Polycrystalline (PC) and single crystalline (SC) samples of La0.7Ca0.3CoO3 (LCCO) with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We conducted isothermal magnetization measurements of the PC and SC samples at temperatures from 2.8 K to 140 K, and evaluated the magnetic entropy change (−ΔSM) under zero field cooling (ZFC) and field cooling (FC) to 2.8 K. An interesting result has been obtained, where the −ΔSM–T curves in the low temperature range show totally different features between the ZFC and FC cooling procedures. The −ΔSM shows a large inverse irreversibility value for the ZFC …
Single-Crystal Growth And Anisotropic Magnetic Properties Of Nonstoichiometric Three-Layer Sodium Cobalt Oxides, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Single-Crystal Growth And Anisotropic Magnetic Properties Of Nonstoichiometric Three-Layer Sodium Cobalt Oxides, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Shi Xue Dou
Large single crystals of α-NaxCoO2 (x=0.91, 0.92, and 0.93) have been successfully fabricated by using the traveling solvent floating zone method. Details on the crystal growth are discussed. The crystal structures were characterized using powder x-ray diffraction and Rietveld refinement. The magnetic susceptibility measurements show that the magnetic properties depend strongly on x. The compound was found to be antiferromagnetic at TN ≈ 20 K for x=0.91 and x=0.92, and paramagnetic for x=0.93. The in-plane and out-of-plane anisotropies were observed for the x=0.91 crystals. In addition, the derived anisotropic g-factor ratios (gab /gc) from the anisotropic susceptibility along H||ab and …
Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou
Magnetocapacitance Effect In Nonmultiferroic Yfe03 Single Crystal, Z X. Cheng, H Shen, J Xu, Peng Liu, S J. Zhang, Jianli Wang, Xiaolin Wang, S X. Dou
Shi Xue Dou
YFeO3 single crystal displays two relaxor-like dielectric relaxations, one at low temperature (170300 K) and one at high temperature (370520 K), which are attributed to the activation of electrons and oxygen vacancies, respectively. Above the temperature at which electrons are activated, the sample displays a large magnetocapacitance effect. Comparison of the impedance Cole-Cole plots measured with and without applied magnetic field reveals that the occurrence of magnetocapacitance effect is accompanied with an increasing in DC conductivity under magnetic field after the activation of electrons, which is explained by the enhancement of electron jumping in Fe2b-O-Fe3b chains by magnetic field. Thus …
Very Strong Intrinsic Flux Pinning And Vortex Avalanches In (Ba, K)Fe2as2 Superconducting Single Crystals, Xiaolin Wang, Shaban R. Ghorbani, Sung-Ik Lee, S X. Dou, C T Lin, T H. Johansen, K.H Muller, Zhenxiang Cheng, Germanas Peleckis, M Shabazi, A.J Qviller, V Yurchenko, G.L Sun, D.L Sun
Very Strong Intrinsic Flux Pinning And Vortex Avalanches In (Ba, K)Fe2as2 Superconducting Single Crystals, Xiaolin Wang, Shaban R. Ghorbani, Sung-Ik Lee, S X. Dou, C T Lin, T H. Johansen, K.H Muller, Zhenxiang Cheng, Germanas Peleckis, M Shabazi, A.J Qviller, V Yurchenko, G.L Sun, D.L Sun
Shi Xue Dou
We report that the (Ba,K)Fe2As2 crystal with Tc=32 K shows a pinning potential, U0, as high as 104 K, with U0 showing very little field dependence. The (Ba,K)Fe2As2 single crystals become isotropic at low temperatures and high magnetic fields, resulting in a very rigid vortex lattice, even in fields very close to Hc2. The isotropic rigid vortices observed in the two-dimensional (2D) (Ba,K)Fe2As2 distinguish this compound from 2D high-Tc cuprate superconductors with 2D vortices. The vortex avalanches were also observed at low temperatures in the (Ba,K)Fe2As2 crystal. It is proposed that it is the K substitution that induces both almost …
Flux Pinning And Vortex Transitions In Doped Bafe2as2 Single Crystals, S R. Ghorbani, X L. Wang, M Shabazi, S X. Dou, K Y. Choi, C T. Lin
Flux Pinning And Vortex Transitions In Doped Bafe2as2 Single Crystals, S R. Ghorbani, X L. Wang, M Shabazi, S X. Dou, K Y. Choi, C T. Lin
Shi Xue Dou
The vortex liquid-to-glass transition has been studied in Ba0.72K0.28Fe2As2 (BaK-122), Ba(Fe0.91Co0.09)2As2(BaCo-122), and Ba(Fe0.95Ni0.05)2As2(BaNi-122) single crystal with superconducting transition temperature, Tc=31.7, 17.3, and 18 K, respectively, by magnetoresistance measurements. For temperatures below Tc, the resistivity curves were measured in magnetic fields within the range of 0≤B≤13 T, and the pinning potential was scaled according to a modified model for vortex liquid resistivity. Good scaling of the resistivity q(B, T) and the effective pinning energy U0(B,T) were obtained. The vortex state is three-dimensional at temperatures lower than a characteristic temperature T*. The vortex phase diagram was determined based on the evolution of …
Josephson-Vortex Flow Resistance In Bi2sr2ca2cu3oy Single Crystals And Its Possible Application In The Manipulation Of Spin And Charge Textures In Diluted Magnetic Semiconductors, Xiaolin Wang, C T Lin, B Liang, S Yu, S Ooi, K Hirata, S Y Ding, Dongqi Shi, S X. Dou, Zhi W. Lin, Jian G. Zhu
Josephson-Vortex Flow Resistance In Bi2sr2ca2cu3oy Single Crystals And Its Possible Application In The Manipulation Of Spin And Charge Textures In Diluted Magnetic Semiconductors, Xiaolin Wang, C T Lin, B Liang, S Yu, S Ooi, K Hirata, S Y Ding, Dongqi Shi, S X. Dou, Zhi W. Lin, Jian G. Zhu
Shi Xue Dou
In this work, the flow of the Josephson vortices (JVs) has been studied for the highly anisotropic Bi2Sr2Ca2Cu3Oy (Bi2223) single crystals. A giant flow of JVs or giant positive magnetoresistance (MR) of over 500%-2000% was obtained in fields of 0.1-5 T and remained almost constant over a wide temperature range from 110 down to 4 K, in contrast to superconducting vortices (SVs), which only produced MR in the vicinity of Tc. The flow of the JVs is expected to be much faster than that of SVs. It is proposed that the Josephson vortices could be used to manipulate the spin …
Magnetic Anisotropy Of Naxcoo2 Single Crystals, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Magnetic Anisotropy Of Naxcoo2 Single Crystals, Dapeng Chen, Xiaolin Wang, C T Lin, S X. Dou
Shi Xue Dou
We report the magnetic properties of single crystals of NaxCoO2 (x=0.42, 0.82, and 0.87). The magnetic susceptibility measurements revealed considerable anisotropy along H parallel to ab and H parallel to c for the as-grown single crystals. It was found that an antiferromagnetic transition with a Neel temperature T-N=21 K occurred for the x=0.82 sample, and there was a paramagnetic phase for the x=0.87 sample over a wide temperature range from 2 to 300 K, but the sample with x=0.42 shows a monotonic increase of chi with increasing temperature above similar to 100 K. In addition, the x=0.82 sample has the …