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A MgB2 superconducting tape has been successfully prepared by a new way of boron diffusion into Mg tape. This tape superconductor has a Tc of 39 K with a sharp transition width of 0.4 K, high bulk critical current density jc of 6.7*10^5…

Superconductivity · Physics 2007-05-23 G. C. Che , S. L. Li , Z. A. Ren , L. Li , S. L. Jia , Y. M. Ni , H. Chen , C. Dong , J. Q. Li , H. H. Wen , Z. X. Zhao

Promising results reported in our previous works led us to think that production of B powder plays a crucial role in MgB2 synthesis. A new method for boron preparation has been developed in our laboratory. This particular process is based…

The MgB2 superconductor synthesized in a flowing argon atmosphere using nanometer magnesium powder as the raw materials, denoted as Nano-MgB2, has been studied by the technique of in-situ high temperature resistance measurement (HT-RT…

Superconductivity · Physics 2009-11-10 Chinping Chen , Zeng-jun Zhou , Xing-guo Li , Jun Xu , Yu-hao Wang , Yong-zhong Wang , Qing-rong Feng

The influence of the nature of the boron precursor on the superconducting properties of polycrystalline MgB2 was studied. Critical current densities for the MgB2 made from high purity amorphous boron are at least a factor of three higher…

Superconductivity · Physics 2009-11-11 S. K. Chen , K. A. Yates , M. G. Blamire , J. L. MacManus-Driscoll

The Powder-In-Tube process has been employed to fabricate tape-like conductors with a strong metallic sheath and based on the newly discovered MgB2 superconducting phase. Long superconducting tapes have been prepared by packing reacted MgB2…

Superconductivity · Physics 2009-11-07 G. Grasso , A. Malagoli , C. Ferdeghini , S. Roncallo , V. Braccini , M. R. Cimberle , A. S. Siri

The effect of the quality of starting powders on the microstructure and superconducting properties of in-situ processed Fe-sheathed MgB2 tapes has been investigated. Three different types of commercial atomized spherical magnesium powder…

Superconductivity · Physics 2009-11-13 Dongliang Wang , Yanwei Ma , Zhengguang Yu , Zhaoshun Gao , Xianping Zhang , K. Watanabe , E. Mossang

Sintered powders and wires of superconducting $MgB_2$ have been fabricated under a variety of conditions in order to determine details of the diffusion of the $Mg$ into $B$ and to study the types of defects that arise during growth. For…

MgB2 wires and tapes suffer from a limitation of the transport current densities, especially at low field, due to an unsufficient thermal stabilization caused by hot spots from a non-homogeneous microstructure, the presence of secondary…

Superconductivity · Physics 2018-07-04 S. I. Schlachter , W. Goldacker , J. Reiner , S. Zimmer , B. Liu , B. Obst

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 have successfully prepared the MgB2 superconducting bulk and powdered materials by the method of combustion synthesis. The starting materials used in this study were powders of Mg and B. X-ray powder diffraction pattern was well assigned…

Superconductivity · Physics 2016-08-31 Yoshihiko Takano , Nobutaka Oguro , Yoshinari Kaieda , Kazumasa Togano

Thin films of MgB2 superconductor were prepared by three different procedures on sapphire and silicon substrates. Boron thin films, ex-situ annealed in magnesium vapour, resulted in textured polycrystalline films with crystal dimensions…

Superconductivity · Physics 2009-11-07 A. Plecenik , L. Satrapinsky , P. Kus , S. Gazi , S. Benacka , I. Vavra , I. Kostic

Two new methods to produce nanopowders of B12P2 boron subphosphide by self-propagating high-temperature synthesis have been proposed. Bulk polycrystalline B12P2 with microhardness of HV = 35(3) GPa and stability in air up to 1300 K has been…

Superconducting MgB2 thin films were prepared on Al2O3(0001) and MgO(100) substrates. Boron thin films were deposited by the electron-beam evaporation followed by post-annealing process with magnesium. Proper post annealing conditions were…

Superconductivity · Physics 2009-11-07 S. H. Moon , J. H. Yun , H. N. Lee , J. I. Kye , H. G. Kim , W. Chung , B. Oh

Superconducting MgB2 thin films were fabricated on Al2O3(0001) substrates under an ex-situ processing conditions. Boron thin films were deposited by pulsed laser deposition followed by a post-annealing process. Resistance measurements of…

Superconductivity · Physics 2019-08-17 S. F. Wang , S. Y. Dai , Y. L. Zhou , Z. H. Chen , D. F. Cui , J. D. Yu , M. He , H. B. Lu , G. Z. Yang

Nanocarbon-doped Fe-sheathed MgB2 tapes with different doping levels were prepared by the in situ powder-in-tube method. Compared to the undoped tapes, Jc for all the C-doped samples was enhanced by more than an order of magnitude in…

Superconductivity · Physics 2009-11-11 Yanwei Ma , Xianping Zhang , G. Nishijima , K. Watanabe , Xuedong Bai

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

Here we report a systematic study of superconductive properties of mono-filamentary MgB2-based wires, manufactured with different filling technique. A detailed comparison of the influence of filling technique and final heat treatment on…

Superconductivity · Physics 2014-07-09 Gianmarco Bovone , Davide Nardelli , Davide Matera , Maurizio Vignolo

$MgB_2$ 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…

The MgB2 bulks were prepared by high energy milling of Mg and B powder. The correlations among milling times, microstructure and superconducting properties were investigated in MgB2 bulks. Samples were characterized by x-ray diffraction…

Superconductivity · Physics 2008-01-14 Y. F. Wu , Y. F. Lu , G. Yan , J. S. Li , Y. Feng , H. P. Tang , S. K. Chen , H. L. Xu , C. S. Li , P. X. Zhang

In the present paper we report an in-situ high-energy X-ray diffraction analysis of MgB2 tapes during the preparation process. The experiment was performed in a specifically designed furnace working in reducing atmosphere, compatible with…

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