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Related papers: Anisotropic s-wave superconductivity in MgB_2

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Two-band superconductivity has become an important topic over the last ten years. Extensive experimental and theoretical studies started with MgB2 and are now focused on the iron-based and other new superconductors. In this review, I…

Superconductivity · Physics 2014-02-18 M. Zehetmayer

We present magnetic susceptibility and electrical transport measurements of the highly anisotropic compound LaSb$_2$ observing a very broad transition into a clean, consistent with type-I, superconducting state with distinct features of 2…

Superconductivity · Physics 2010-11-22 S. Guo , D. P. Young , P. W. Adams , X. S. Wu , J. Y. Chan , G. T. McCandless , J. F. DiTusa

We synthesized single crystalline and policrystalline MgB_2 under ambient pressures. The single crystals of MgB_2 were of good quality, where the crystal structure refinements were successfully converged with R = 0.020. The specific heat of…

Superconductivity · Physics 2009-11-07 Y. Machida , S. Sasaki , H. Fujii , M. Furuyama , I. Kakeya , K. Kadowaki

In this paper we introduce a novel method for fabricating MgB$_2$/MgO multilayers and demonstrate the potential for using them as a new model for disordered superconductors. In this approach we control the annealing of the MgB$_2$ to yield…

Superconductivity · Physics 2009-11-13 W. Siemons , M. A. Steiner , G. Koster , D. H. A. Blank , M. R. Beasley , A. Kapitulnik

High-quality epitaxial MgB2 thin films prepared by pulsed laser deposition with Tc = 39 K offer the opportunity to study the anisotropy and robustness of the superconducting state in magnetic fields. We measure the in-plane electrical…

Superconductivity · Physics 2009-11-07 M. H. Jung , M. Jaime , A. H. Lacerda , G. S. Boebinger , W. N. Kang , H. J. Kim , E. M. Choi , S. I. Lee

MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…

Superconductivity · Physics 2009-11-07 A. Plecenik , S. Benacka , P. Kus , M. Grajcar

Based on weakly-coupled anisotropic BCS theory, the dependence of energy gap and specific heat on temperature are evaluated for superconductor MgB$_2$, and the results are compared with experimental data.We show that the weak coupling…

Superconductivity · Physics 2007-05-23 Todor M. Mishonov , Valery L. Pokrovsky , Hongduo Wei

We use tunable laser based Angle Resolved Photoemission Spectroscopy to study the electronic structure of the multi-band superconductor, MgB2. These results form the base line for detailed studies of superconductivity in multi-band systems.…

Superconductivity · Physics 2017-03-21 Daixiang Mou , Rui Jiang , Valentin Taufour , S. L. Bud'ko , P. C. Canfield , Adam Kaminski

The review considers bulk MgB2-based materials in terms of their structure, superconducting and mechanical properties. Superconducting transition temperatures of 34.5-39.4 K, critical current densities of 1.8-1.0 x E6 A/sq.cm in self field…

Superconductivity · Physics 2009-12-25 T. A. Prikhna

We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB$_{2}$. Experiments are proposed which lead to identification of the possible scenarios: whether both $\sigma $- and $\pi $-bands superconduct or $\sigma…

Superconductivity · Physics 2007-05-23 V. A. Ivanov , J. J. Betouras , F. M. Peeters

We have observed the conduction electron spin resonance (CESR) in fine powders of MgB2 both in the superconducting and normal states. The Pauli susceptibility is chi_s=2.0*10^{-5} emu/mole in the temperature range of 450 to 600 K. The spin…

$MgB_2$ becomes superconducting just below 40 K. Whereas porous polycrystalline samples of $MgB_2$ can be synthesized from boron powders, in this letter we demonstrate that dense wires of $MgB_2$ can be prepared by exposing boron filaments…

We report on measurements of the magnetic moment in superconducting MgB2 single crystals. We find \mu_0H_{c2}^c(0) = 3.2 T, \mu_0H_{c2}^{ab}(0) = 14.5 T, \gamma = 4.6, \mu_0H_c(0) = 0.28 T, and \kappa(T_c) = 4.7. The standard…

Superconductivity · Physics 2009-11-07 M. Zehetmayer , M. Eisterer , H. W. Weber , J. Jun , S. M. Kazakov , J. Karpinski , A. Wisniewski

We present extensive Scanning Tunneling Spectroscopy (STM/S) measurements at low temperatures in the multiband superconductor MgB$_2$. We find a similar behavior in single crystalline samples and in single grains, which clearly shows the…

Superconductivity · Physics 2009-11-07 P. Martinez-Samper , J. G. Rodrigo , G. Rubio-Bollinger , H. Suderow , S. Vieira , S. Lee , S. Tajima

Consistent account is provided of strongly anisotropic properties in thermodynamics of MgB$_2$ under magnetic field $H$ using approximate analytic solution in the quasiclassical formalism. With the strength of the pairing interactions and…

Superconductivity · Physics 2009-11-10 Masatoshi Mugikura , Hiroaki Kusunose , Yoshio Kuramoto

Studies on the new MgB2 superconductor, with a critical temperature Tc ~ 39 K, have evidenced its potential for applications although intense magnetic relaxation effects limit the critical current density, Jc, at high magnetic fields. This…

Superconductivity · Physics 2009-11-07 O. F. de Lima , C. A. Cardoso , R. A. Ribeiro , M. A. Avila , A. A. Coelho

We study the new binary intermetallic superconductor MgB2 using high-resolution photo-emission spectroscopy. The superconducting-state spectrum measured at 5.4 K shows a coherent peak with a shoulder structure, in sharp contrast to that…

Superconductivity · Physics 2009-11-07 S. Tsuda , T. Yokoya , T. Kiss , Y. Takano , K. Togano , H. Kitou , H. Ihara , S. Shin

Transport and thermodynamic properties of a sintered pellet of the newly discovered $MgB_2$ superconductor have been measured to determine the characteristic critical magnetic fields and critical current densities. Both resistive transition…

Superconductivity · Physics 2009-11-07 D. K. Finnemore , J. E. Ostenson , S. L. Bud'ko , G. Lapertot , P. C. Canfield

Samples of aligned MgB2 crystallites have been prepared, allowing for the first time the direct identification of an upper critical field anisotropy Hc2^{ab}/Hc2^{c}= xi_{ab}/xi_{c} ~ 1.73; with xi_{o,ab} ~ 70 A, xi_{o,c} ~ 40 A, and a mass…

Superconductivity · Physics 2009-11-07 O. F. de Lima , R. A. Ribeiro , M. A. Avila , C. A. Cardoso , A. A. Coelho

The superconducting properties of copper-sheathed MgB2 wires fabricated by conventional powder-in-tube techniques and the in-situ reaction procedure are analysed. The influence of the processing conditions and initial (1+x)Mg + 2B (x = 0,…

Superconductivity · Physics 2007-05-23 E. Martinez , R. Navarro