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Related papers: Superconducting MgB2 thin films nano-bridges for c…

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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

In this paper, we analyze the upper critical field of four MgB2 thin films, with different resistivity (between 5 to 50 mWcm) and critical temperature (between 29.5 to 38.8 K), measured up to 28 Tesla. In the perpendicular direction the…

Superconductivity · Physics 2007-05-23 V. Ferrando , C. Tarantini , P. Manfrinetti , D. Marre' , M. Putti , A. Tumino , C. Ferdeghini

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

Highly dense nanocrystalline MgB_2 bulk superconductors with distinctly improved pinning were prepared by mechanical alloying of Mg and B powders and hot compaction at ambient temperatures. The nanocrystalline samples reveal high critical…

Superconductivity · Physics 2009-11-07 A. Gümbel , J. Eckert , G. Fuchs , K. Nenkov , K. -H. Müller , L. Schultz

$MgB_2$ 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…

Porous magnesium diboride samples have been prepared by the heat treatment of a pressed mixture of Mg and MgB2 powders. It was found that linked superconducting structure is formed down to the minimum normalized density gamma= d/do= 0.16…

Superconductivity · Physics 2009-11-11 V. A. Grinenko , E. P. Krasnoperov , V. A. Stoliarov , A. A. Bush , B. P. Mikhajlov

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 discovery of superconductivity at 39 K in MgB2[1] raises many issues. One of the central questions is whether this new superconductor resembles a high-temperature-cuprate superconductor or a low-temperature metallic superconductor in…

In DC and AC practical applications of MgB2 superconducting wires an important role is represented by the material sheath which has to provide, among other things, a suitable electrical and thermal stabilization. A way to obtain a large…

Superconductivity · Physics 2008-07-22 A Malagoli , M Tropeano , V Cubeda , C Bernini , V Braccini , C Fanciulli , G Romano , M Putti , C Ferdeghini

In-plane electrical transport properties of MgB2 single crystals grown under high pressure of 4-6 GPa and temperature of 1400-1700oC in Mg-B-N system have been measured. For all specimens we found sharp superconducting transition around…

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

We develop the multi-band BCS model of superconductivity in the ultrathin films using the orthogonal tight-binding approximation for constructing the electron wavefunctions. This allows for relatively simple determination of the band…

Superconductivity · Physics 2014-07-15 Karol Szałowski

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

Ruthenium dioxide (RuO$_2$) thin films were synthesized by Chemical Solution Deposition (CSD) on silicon substrates using only water and acetic acid as solvents. The microstructure, phase-purity, electrical and optical properties as well as…

The superconducting and critical current properties of thin films of NiBi3 formed on the surface of carbon microfibers and sapphire substrates are reported. The NiBi3 coated carbon microfibers were prepared by reacting 7 {\mu}m diameter…

Superconductivity · Physics 2013-03-28 N. Haldolaarachchige , Y. M. Xiong , P. W. Adams , D. P. Young

The effect of water exposure on MgB2 is studied by submerging an 800 nm thick MgB2 film into deionized water at room temperature for 1 hour, 4 hours, 10 hours, and 15 hours, and by analyzing the resulting material using scanning electron…

Superconductivity · Physics 2007-05-23 H Y Zhai , H M Christen , L Zhang , M Paranthaman , P H Fleming , D H Lowndes

Magnesium diboride (MgB2) thin films are a potential alternative to low-temperature superconductors (LTS) due to a higher critical temperature (Tc) of approximately 39 K. The reactive evaporation deposition technique also affords relatively…

Superconductivity · Physics 2015-05-19 Chris S. Yung , Brian H. Moeckly

The in-situ growth of superconducting MgB2 thin films was examined from various perspectives. The paper discusses (1) growth temperature, (2) the effect of excess Mg, (3) the effect of residual gas during growth, (4) the effect of in-situ…

Superconductivity · Physics 2009-11-07 K Ueda , M. Naito

MgB2 hollow wires have been produced with a new technique which uses a conventional wire manufacturing process but is applied to composite billets containing the elemental B and Mg precursors in an appropriate shape. The technique has been…

Superconductivity · Physics 2009-11-07 G. Giunchi , S. Ceresara , G. Ripamonti , A. DiZenobio , S. Rossi , S. Chiarelli , M. Spadoni , R. Wesche , P. L. Bruzzone

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 properties of thin films can be vastly different from those of bulk materials. Seminal work has shown the critical temperature Tc of elemental superconductors decreases with decreasing film thickness when the normal-state…