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Related papers: Fully dense MgB_2 superconductor textured by hot d…

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We succeeded in the synthesis of high-Jc MgB2 bulks via high energy ball-milling of elemental Mg and B powder at ambient temperatures. Alternatively to longtime mechanical alloying technique, the mixed powder was ball-milled for only 1h and…

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

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…

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

Dense pure and doped (Mg1-xAx)B2 samples with A = Na, Ca, Cu, Ag, Zn and Al were synthesized at high pressure - high temperature in a multi anvils press (3.5-6 GPa, 900-1000C) for x up to 0.20. They were studied by x-ray diffraction,…

Superconductivity · Physics 2007-05-23 P. Toulemonde , N. Musolino , H. L. Suo , R. Flukiger

Superconducting MgB2 thin films were prepared on 50-micrometer-thick, flexible polyamide Kapton-E foils by vacuum co-deposition of Mg and B precursors with nominal thickness of about 100 nm and a special ex-situ rapid annealing process in…

Superconductivity · Physics 2009-11-07 P. Kus , A. Plecenik , L. Satrapinsky , Y. Xu , R. Sobolewski

An important predicted, but so far uncharacterized, property of the new superconductor MgB2 is electronic anisotropy arising from its layered crystal structure. Here we report on three c-axis oriented thin films, showing that the upper…

We have successfully synthesized MgB2 thick films on 4H-SiC substrate by hybrid physical-chemical deposition (HPCVD). The films have transition temperature TC above 40 K. X-ray diffraction (XRD) shows the c-axis oriented structure of MgB2,…

Superconductivity · Physics 2009-11-11 Fen Li , Tao Guo , Kaicheng Zhang , Li-ping Chen , Chinping Chen , Qing-rong Feng

We report on study of the electronic anisotropy of the newly discovered MgB2 superconductor using the in-plane resistivity measurements in magnetic field applied perpendicular and parallel to Mg and B planes of MgB2 single crystals. The…

Superconductivity · Physics 2009-11-07 Yu. Eltsev , S. Lee , K. Nakao , N. Chikumoto , S. Tajima , N. Koshizuka , M. Murakami

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

A c-axis oriented thin film and a high density sintered pellet of MgB2 have been studied by x-ray photoemission spectroscopy, and compared to measurements from MgO and MgF2 single crystals. The as-grown surface has a layer which is Mg-rich…

Superconductivity · Physics 2009-11-07 R. P. Vasquez , C. U. Jung , Min-Seok Park , Heon-Jung Kim , J. Y. Kim , Sung-Ik Lee

Heat-capacity measurements of a 39 microgramm MgB_2 single crystal in fields up to 14 T and below 3 K allow the determination of the low-temperature linear term of the specific heat, its field dependence and its anisotropy. Our results are…

Superconductivity · Physics 2009-11-07 F. Bouquet , Y. Wang , I. Sheikin , T. Plackowski , A. Junod , S. Lee , S. Tajima

The MgB2 coated superconducting tapes have been fabricated on textured Cu (0 0 1) and polycrystalline Hastelloy tapes using coated conductor technique, which has been developed for the second generation high temperature superconducting…

Superconductivity · Physics 2015-06-03 Mahipal Ranot , W. N. Kang

Nanocrystalline MgB$_2$ produced by mechanical alloying has been shown to exhibit enhanced superconducting properties such as increased pinning and higher critical currents. However, the effects of the synthesis process on the intrinsic…

Superconductivity · Physics 2009-11-11 B Lorenz , O Perner , J Eckert , C W Chu

Despite the intense activity in the year since the discovery of superconductivity in MgB2, key parameters, in particular the upper and lower critical fields Hc2 and Hc1 and their anisotropies, are not well-established, largely because of…

Superconductivity · Physics 2009-11-07 G. K. Perkins , J. Moore , Y. Bugoslavsky , L. F. Cohen , J. Jun , S. M. Kazakov , J. Karpinski , A. D. Caplin

The temperature dependence of the magnetic field distribution in the mixed superconducting phase of randomly oriented MgB$_2$ powder was probed by $% ^{11}$B NMR spectroscopy. Below the temperature of the second critical ($B_{% {c2}}$)…

Superconductivity · Physics 2009-11-07 G. Papavassiliou , M. Pissas , M. Fardis , M. Karayanni , C. Christides

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

Superconducting thin films of magnesium diboride (MgB$_2$) were prepared on MgO (001) substrate by a molecular beam epitaxy (MBE) method with the co-evaporation conditions of low deposition rate in ultra-high vacuum. The structural and…

Superconductivity · Physics 2007-05-23 Y. Harada , M. Udsuka , Y. Nakanishi , M. Yoshizawa

The synthesis of MgB2-based materials under high pressure gave the possibility to suppress the evaporation of magnesium and to obtain near theoretically dense nanograined structures with high superconducting, thermal conducting, and…

We introduce a simple method of an MgB2 film preparation using sequential electron-beam evaporation of B-Mg two-layer (followed by in-situ annealing) on the NbN buffered Si(100) substrate. The Transmission Electron Microscopy analyses…

Here we report the growth of sub-millimeter MgB2 single crystals of various shapes under high pressure in Mg-B-N system. Structure refinement using a single-crystal X-ray diffraction analysis gives lattice parameters a=3.0851(5) A and…

Superconductivity · Physics 2009-11-07 S. Lee , H. Mori , T. Masui , Yu. Eltsev , A. Yamamoto , S. Tajima