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Related papers: Comparative Study of Dense Bulk MgB$_2$ Materials …

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The processing of binary alloys consisting of ferromagnetic Fe and antiferromagnetic Cr by severe plastic deformation (SPD) with different chemical compositions has been investigated. Although the phase diagram exhibits a large gap in the…

Materials Science · Physics 2021-01-12 Lukas Weissitsch , Martin Stückler , Stefan Wurster , Reinhard Pippan , Andrea Bachmaier

The effect of high magnetic fields on the current carrying properties of both MgB2 bulks and Fe-sheathed tapes was investigated following different thermal sequences. It is found that application of a large magnetic field during processing…

Superconductivity · Physics 2009-11-11 Yanwei Ma , Aixia Xu , Xianping Zhang , Xiaohang Li , S. Awaji , K. Watanabe

Low resistivity ("clean") MgB2 bulk samples annealed in Mg vapor show an increase in upper critical field Hc2(T) and irreversibility field Hirr(T) by a factor of 2 in both transport and magnetic measurements. The best sample displayed Hirr…

Superconductivity · Physics 2009-11-07 V. Braccini , L. D. Cooley , S. Patnaik , P. Manfrinetti , A. Palenzona , A. S. Siri , D. C. Larbalestier

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

Upper critical fields of several magnesium diboride thin films were measured up to 28 T at the Grenoble High Magnetic Field Laboratory (GHMFL) in Grenoble and up to 60 T at the Laboratoire National des Champs Magnetiques Pulses (LNCMP) in…

The electronic anisotropy in MgB2, is still a not completely clear topic; high quality c-oriented films are suitable systems to investigate this property. In this work we present our results on MgB2 superconducting thin films grown on MgO…

In this letter, we report the first successful fabrication of dense, metal-clad MgB2 superconductor wires as well as the first demonstration of high transport Jc of greater than 36,000 A/cm2 in MgB2. The fabrication technique that we…

Superconductivity · Physics 2007-05-23 S. Jin , H. Mavoori , R. B. van Dover

We report the temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high temperature and high pressure condition. The superconducting transition width for the resistivity measurement was about 0.4 K, and the low-field…

Superconductivity · Physics 2009-11-07 C. U. Jung , Min-Seok Park , W. N. Kang , Mun-Seog Kim , S. Y. Lee , Sung-Ik Lee

A relatively high critical temperature, Tc, approaching 40 K, places the recently-discovered superconductor magnesium diboride (MgB2) intermediate between the families of low- and copper-oxide-based high-temperature superconductors (HTS).…

Superconductivity · Physics 2009-11-07 Y. Bugoslavsky , L. F. Cohen , G. K. Perkins , M. Polichetti , T. J. Tate , R. Gwilliam , A. D. Caplin

A novel method to prepare bulk Fe(Se0.5Te0.5) samples is presented, based on a melting process and a subsequent annealing treatment. With respect to the standard sintering technique, it produces much more homogeneous and denser samples,…

Superconducting MgB(2) films with Tc = 38.6 K were prepared using a precursor-deposition, ex-situ post-processing approach. Precursor films of boron, ~0.5 micrometer thick, were deposited onto Al(2)O(3) (102) substrates by e-beam…

We report on specific heat, high magnetic field transport and $ac-$susceptibility measurements on magnesium diboride single crystals. The upper critical field $H_{c2}$ for magnetic fields perpendicular and parallel to the Mg and B planes is…

This review paper illustrates the main normal and superconducting state properties of magnesium diboride, a material known since early 1950's, but recently discovered to be superconductive at a remarkably high critical temperature Tc=40K…

Superconductivity · Physics 2007-05-23 Cristina Buzea , Tsutomu Yamashita

The powder-in-tube MgB2 wires were prepared by high energy milling of Mg and B powder. The powder was not mechanically alloyed for 2h short milling time. However, the MgB2 grains in wires are very small (20 100nm) and resembled to the…

Superconductivity · Physics 2007-05-23 Y. F. Wu , G. Yan , J. S. Li , Y. Feng , S. K. Chen , H. P. Tang , H. L. Xu , C. S. Li , P. X. Zhang , Y. F. Lu

We have grown MgB2 films in a postannealing process. Precursors were prepared on Al2O3(0001) substrates by codeposition of Mg and MgB2 using pulsed laser deposition technique. Superconducting MgB2 thin films were obtained via an ex situ…

Superconductivity · Physics 2007-05-23 Yi Zhao , Yuemeng Chi , Ruijuan Nie , Furen Wang

We investigated the effect of alloying on the upper critical field $H_{c2}$ in 12 $MgB_2$ films, in which disorder was introduced by growth, carbon doping or He-ion irradiation, finding a significant $H_{c2}$ enhancement in C-alloyed films,…

We have fabricated a series of iron-sheathed superconducting wires prepared by the powder-in-tube technique from (MgB_2)_{1-x}:(Mg+2B)_x initial powder mixtures taken with different proportions, so that x varies from 0 to 1. It turned out…

Superconductivity · Physics 2007-05-23 Alexey V Pan , Sihai Zhou , Huakun Liu , Shixue Dou

Thin films of the recently discovered magnesium diboride (MgB2) intermetalic superconducting compound have been grown using a magnetron sputtering deposition technique followed by in-situ annealing at 830 C. High quality films were obtained…

Superconductivity · Physics 2009-11-07 R. Vaglio , M. G. Maglione , R. Di Capua

The superconductivities of samples prepared by several procedures were found to degrade under ambient environment. The degradation mechanism was studied by measuring the change of surface chemical composition of dense MgB2 pellets (prepared…

The MgB2 - based material high-pressure synthesized at 2 GPa and 800 C for 1 h from Mg and B (taken in the stoichiometry ratio of MgB2) with addition of 2-10 wt% of Ti demonstrated the critical current density (jc) higher than 100 kA/cm^2…