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The microstructures of MgB2 wires prepared by the powder-in-tube technique and subsequent hot isostatic pressing were investigated using transmission electron microscopy. Large amount of crystalline defects including small angle twisting,…

Materials Science · Physics 2009-11-10 X. Z. Liao , A. Serquis , Y. T. Zhu , L. Civale , D. L. Hammon , D. E. Peterson , F. M. Mueller , V. F. Nesterenko , Y. Gu

We have determined the structural properties of the superconducting compound MgB2 as a function of temperature from 11 K to 297 K and as a function of hydrostatic pressure up to 0.62 GPa using neutron powder diffraction. This compound, when…

Superconductivity · Physics 2009-11-07 J. D. Jorgensen , D. G. Hinks , S. Short

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…

Superconducting thin films of MgB2 were deposited by Pulsed Laser Deposition on magnesium oxide and sapphire substrates. Samples grown at 450C in an argon buffer pressure of about 10-2 mbar by using a magnesium enriched target resulted to…

Far-infrared reflectivity studies on the polycrystalline intermetallic compound MgB_2 with a superconducting transition temperature T_c=39 K were performed at temperatures 20 K to 300 K. We observe a significant raise of the…

We have developed disk-shaped MgB2 bulk superconducting magnets (20, 30 mm in diameter, 10 mm in thickness) using the in-situ process from Mg and B powders and evaluated the temperature dependence of trapped magnetic field. A pair of two…

Superconductivity · Physics 2012-08-10 A. Yamamoto , A. Ishihara , M. Tomita , J. Shimoyama , K. Kishio

The results of micro-structural and detailed magnetization studies are reported here for our recently published TbSr2Cu2.7Mo0.3O7+d superconductor with a transition temperature (Tc) at as high as 80 K [1]. From XRD and EDX the sample was…

Superconductivity · Physics 2009-11-10 V. P. S. Awana , Anurag Gupta , H. Kishan , M. Karppinen , H. Yamauchi , A. V. Narlikar , E. Galstyan , I. Felner

The distribution of magnetic field in single-phase polycrystalline bulk MgB2 has been measured using a Magneto-Optical (MO) technique for an external magnetic field applied perpendicular to the sample surface. The MO studies indicate that…

Superconductivity · Physics 2009-11-07 K. Kawano , J. S. Abell , M. Kambara , N Hari Babu , D. A. Cardwell

This paper presents a brief review on the reported anisotropic properties of MgB2, in the superconducting state (e.g. upper critical field Hc2, field penetration depth, coherence length, energy gap) as well as in the normal state (e.g.,…

Superconductivity · Physics 2007-05-23 O. F. de Lima

The recent surprising discovery of superconductivity with critical temperature $T_c$ = 32 K in MoB$_2$ above 70 GPa has led to the search for related materials that may superconduct at similarly high $T_c$ values and lower pressures. We…

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

Studied 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10 (Ru-1222) compound crystallized in a tetragonal I4/mmm space group crystal structure. Thermo-gravemetric (TG) analysis of the compound showed the release of oxygen and breaking to metallic…

Superconductivity · Physics 2009-11-07 V. P. S. Awana , E. Takayama-Muromachi , M. Karppinen , H. Yamauchi

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…

Transport current values of 7.5 x 104 A/cm2 at 4.2 K and self-field are reported for MbB2-based tapes. MgB2 strands were formed by directly filling commercially available MgB2 powder into Nb-lined, monel tubes and wire drawing. The wires…

Superconductivity · Physics 2007-05-23 M. D. Sumption , X. Peng , E. Lee , M. Tomsic , E. W. Collings

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

Superconducting MgB2 was synthesized in a stainless steel tube which compressed by pulsed magnetic field. The temperature dependence of diamagnetic moment m(T) was investigated and the pinning potential was determined

Superconductivity · Physics 2007-05-23 S. P. Ananev , V. A. Grinenko , V. A. Keilin , E. P. Krasnoperov , P. A. Levit , V. A. Stoliarov

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

Considerable excitement has been caused recently by the discovery that the binary boride system with stoichiometry MgB2 is superconducting at the remarkably high temperature of 39 K (1). This potentially opens the way to even higher Tc…

The critical current density of four MgB2 samples was measured inductively and for one of them also by transport. Pure phased and dense bulk samples yield a critical current density which in value, as well as in its magnetic field and…

Since the discovery of MgB2 with Tc=39K, various metal diborides of MB2 have been intensively studied to find possible conventional high-temperature superconductors. A possible 2D structure of the metal diboride has been shown to be in the…

Superconductivity · Physics 2024-12-19 Jakkapat Seeyangnok , Udomsilp Pinsook , Graeme John Ackland