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

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We studied the influence of sample preparation and defects in the superconducting properties samples using atomic ratios of Mg:B=1:1 and Mg:B=1:2. Samples were characterized by SEM, and XRD, and the magnetization properties were examined in…

We report the synthesis and physical properties of a full Heusler compound, MgPd$_2$Sb, which we found to show superconductivity below $T_c$ = 2.2 K. MgPd$_2$Sb was obtained by a two-step solid-state reaction method and its purity and cubic…

We have successfully deposited thick MgB2 film on the (0001) crystalline surface of sapphire by the method of hybrid physical-chemical vapor deposition (HPCVD). The film thickness is about 1.3 micron. It has a dense and interlaced…

Superconductivity · Physics 2009-11-11 Kaicheng Zhang , Li-li Ding , Cheng-gang Zhuang , Li-ping Chen , Chinping. Chen* , Qing-rong Feng

Fine grained polycrystalline samples of MgB(2) superconductor were synthesized from the elements to contain < 5 % of impurity phases, according to X-ray powder diffractometry. The superconductive transition was sharp with a midpoint Tc =…

Superconductivity · Physics 2007-05-23 J. R. Thompson , M. Paranthaman , D. K. Christen , K. D. Sorge , H. J. Kim , J. G. Ossandon

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…

We fabricated superconducting MgB2 thin films on (001) MgO substrates. The samples were prepared by magnetron rf and dc co-sputtering on heated substrates. They were annealed ex-situ for one hour at temperatures between 450{\deg}C and…

Superconductivity · Physics 2010-10-27 Savio Fabretti , Patrick Thomas , Markus Meinert , Andy Thomas

A new two-dimensional material { Mg2B4C2, belonging to the family of the conventional superconductor MgB2, is theoretically predicted to exhibit superconductivity with critical temperature Tc estimated in the 47-48 K range (predicted using…

Superconducting thin films have been prepared in a two-step in-situ process, using the Mg-B plasma generated by pulsed laser ablation. The target was composed of a mixture of Mg and MgB2 powders to compensate for the volatility of Mg and…

Superconductivity · Physics 2009-11-07 D. H. A. Blank , H. Hilgenkamp , A. Brinkman , D. Mijatovic , G. Rijnders , H. Rogalla

The specific heat C of a sintered polycrystalline sample of MgB2 with a bulk superconducting transition temperature Tc=36.7 K is measured as a function of the temperature (2-300 K) and magnetic field (0-16 T), together with magnetic…

Superconductivity · Physics 2009-11-07 Y. Wang , T. Plackowski , A. Junod

High-pressure electrical resistivity measurements reveal that the mechanical deformation of ultra-hard WB2 during compression induces superconductivity above 50 GPa with a maximum superconducting critical temperature, Tc of 17 K at 90 GPa.…

Recently, we have reported that a highly disordered fractal MgO/MgB2 nanocomposite exhibits bulk-like superconducting properties with isotropic pinning, showing an excellent phase-coherent capability irrespective of the low volume fraction…

We report on quantitative calculations of the upper critical field $H_{c2}$ for clean type-II superconductors Nb, NbSe$_{2}$, and MgB$_{2}$ using Fermi surfaces from {\em ab initio} electronic structure calculations. The results for Nb and…

Superconductivity · Physics 2009-11-10 Masao Arai , Takafumi Kita

We employ ab initio modeling to investigate the possibility of attaining high-temperature conventional superconductivity in ambient-pressure materials based on the known MgB$_2$C$_2$ and recently proposed thermodynamically stable NaBC…

Sandwich-type MgB2 Josephson tunnel junctions (MgB2/AlOx/MgB2) have been fabricated using as-grown MgB2 films formed by molecular beam epitaxy. The junctions exhibited substantial supercurrent and a well-defined superconducting gap…

Superconductivity · Physics 2007-05-23 K. Ueda , S. Saito , K. Semba , T. Makimoto , M. Naito

The hydrostatic pressure effect on the newly discovered superconductor MgB2 has been determined. The transition temperature Tc was found to decrease linearly at a large rate of -1.6 K/GPa, in good quantitative agreement with the ensuing…

Superconductivity · Physics 2009-11-07 B. Lorenz , R. L. Meng , C. W. Chu

A thin film technology compatible with multilayer device fabrication is critical for exploring the potential of the 39-K superconductor magnesium diboride for superconducting electronics. Using a Hybrid Physical-Chemical Vapor Deposition…

Based on a detailed modeling of the Fermi surface topology of MgB2 we calculated the anisotropy of the upper critical field Bc2 within the two gap model. The sigma-band is modeled as a distorted cylinder and the pi-band as a half-torus,…

Superconductivity · Physics 2007-05-23 T. Dahm , S. Graser , N. Schopohl

The high resistivity of many bulk and film samples of MgB2 is most readily explained by the suggestion that only a fraction of the cross-sectional area of the samples is effectively carrying current. Hence the supercurrent (Jc) in such…

Superconductivity · Physics 2009-11-10 J. M. Rowell , S. Y. Xu , X. H. Zeng , A. V. Pogrebnyakov , Q. Li , X. X. Xi , J. M. Redwing , W. Tian , X. Pan

This work studies the influence of microstructures and crystalline defects on the superconductivity of MgB2, with the objective to improve its flux pinning. A MgB2 sample pellet that was hot isostatic pressed (HIPed) was found to have…

Materials of the Y-Ba-Cu-O (melt-textured YBa2Cu3O7-d-based materials or MT-YBCO) and Mg-B-O (MgB2-based materials) systems with high superconducting performance, which can be attained due to the formation of regularly distributed…