The outline design of a fully superconducting motor for liquid hydrogen pump with a magnesium-diboride (MgB2) superconducting wire is carried out to present various advantages arising from its prospective performances. The squirrel-cage rotor winding composed of superconducting loops with the MgB2 wire enables us to operate the motor not only in a slip mode but also in a synchronous rotation mo...

Superconductivity of boron-doped diamond, reported recently at T(c)=4 K, is investigated exploiting its electronic and vibrational analogies to MgB2. The deformation potential of the hole states arising from the C-C bond-stretch mode is 60% larger than the corresponding quantity in MgB2 that drives its high T(c), leading to very large electron-phonon matrix elements. The calculated coupling str...

A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances H_{c2}, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in J_{c}. The irreversibility fie...

The superconducting-gap of MgB2 has been studied by high-resolution angle-resolved photoemission spectroscopy. The results show that superconducting gaps with values of 5.5 and 2.2 meV open on the sigma band and the pi band, respectively, but both the gaps close at the bulk transition temperature, providing a definitive experimental evidence for the two-band superconductivity with strong interb...

The influence of different boron precursor powders on the critical current density of MgB2 superconductor with added Ni-Co-B nanoparticles is investigated. Different types of boron have different morphologies, particle sizes and impurity content, all of which have a strong impact on the critical current density ( Jc). The boron samples investigated in this study include three different boron po...

Comparative analysis of structural and electromagnetic characteristics have been performed on nano SiCand polycarbosilane-doped MgB2 samples prepared by the dry and liquid mixing approaches. The total benefit of liquid mixing approach for fabrication of “organic” MgB2 superconductor with excellent electromagnetic performance has been demonstrated.

The past ¿fteen years have witnessed some of the more memorable discoveries in the ninety-year-old ¿eld of superconductivity, including the high-AS oxides in 1986 [1], the alkali-doped fullerenes in 1991 [2], the charge-injected fullerenes in 2000 [3], and the binary compound MgB2 in January 2001 [4]. The discovery of superconductivity at such high temperatures (40 K) in the simple rc R-metal c...

We have studied bulk MgB2 synthesized by reaction of MgH2 and B with and without SiC nanoparticles and at a range of reaction temperatures. All of the samples showed enhanced upper critical fields compared to most bulk MgB2, including the sample with 10 at. % SiC reacted at 600 °C, which showed Hc2 0 K 42 T. Extensive transmission electron microscopy TEM and STEM observations show that using Mg...

Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging (MRI). The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demo...

We present a comparison of electron-phonon interaction in NbB2 and MgB2, calculated using full-potential, density-functional-based methods in P6/mmm crystal structure. Our results, described in terms of (i) electronic structure, (ii) phonon density of states F (ω), (iii) Eliashberg function α2F (ω), and (iv) the solutions of the isotropic Eliashberg gap equation, clearly show significant differ...