Related papers: MgB2 synthesis in closed volume and pinning potent…
MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…
The recently discovered superconductivity in MgB2 has created the world sensation. In spite of the relatively high superconducting transition temperature Tc=39K, the superconductivity is understood in terms of rare two gap superconductor…
A trapped field of over 3 T has been measured at 17.5 K in a magnetised stack of two disc-shaped bulk MgB2 superconductors of diameter 25 mm and thickness 5.4 mm. The bulk MgB2 samples were fabricated by uniaxial hot pressing, which is a…
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…
Superconducting thin films have been prepared on Si-substrates, using pulsed laser deposition from a target composed of a mixture of Mg and MgB2 powders. The films were deposited at room temperature and post-annealed at 600 degrees C. The…
Magnetization studies have been carried out on superconducting MgB$_2$ (T$_c$=37K) in the temperature range of 2-50K and in magnetic field up to 5 Tesla. From these measurements, values of the lower critical field H$_c1$(0), upper critical…
By doping MgB_2 superconductor with SiC nano-particles, we have successfully introduced pinning sites directly into the crystal lattice of MgB_2 grains (intra-grain pinning). It became possible due to the combination of counter-balanced Si…
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 with Tc above 9 K was found in metal-deficient NbB2 prepared under 5 GPa, while no clear superconductivity was observed down to 3 K in stoichiometric NbB2. The superconductivity was observed above x = 0.04 in Nb1-xB2. and…
Magneto-optical imaging reveals that in superconducting films of MgB2 a transport current creates avalanche-like flux dynamics where highly branching dendritic penetration patterns are formed. The instability is triggered when the current…
We report an ultra-low resistance superconducting joint using unreacted multifilament MgB2 wires produced by tailoring the powder compaction pressure within the joint with heat treatment conditions. The joint demonstrated an ultra-low…
We present a study on the power dependence of the microwave surface impedance in thin films of the novel superconductor MgB2. 500 nm thick samples exhibiting critical temperatures ranging between 26 and 38 K are synthesized by an ex-situ…
As-grown superconducting thin films of MgB2 were prepared by molecular beam epitaxy (MBE), and studied by X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). Only films prepared at temperatures between 150 and 320 deg. showed…
The size effect of the raw B powder on the MgB2 phase formation has been studied by the technique of in-situ high temperature resistivity (HT-rT) measurement. The onset temperature, Tonset, and the completion temperature, TPF, of the phase…
0.5 to 5.0 wt.% Dy2O3 was in-situ reacted with Mg + B to form pinned MgB2. While Tc remained largely unchanged, Jc was strongly enhanced. The best sample (only 0.5 wt.% Dy2O3) had a Jc of 6.5 x 10^5 A/cm^2 at 6K, 1T and 3.5 x 10^5 A/cm^2 at…
Superconducting MgB2 thin films were fabricated on Al2O3(0001) substrates under an ex-situ processing conditions. Boron thin films were deposited by pulsed laser deposition followed by a post-annealing process. Resistance measurements of…
Recently it was discovered that, under elevated pressures, MoB$_2$ exhibits superconductivity at a critical temperature, $T_c$, as high as 32 K. The superconductivity appears to develop following a pressure-induced structural transition…
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…
We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a…
A relatively high critical temperature, Tc, approaching 40 K, places the recently-discovered superconductor magnesium diboride (MgB2) intermediate between the families of low- and copper-oxide-based high-temperature superconductors (HTS).…