Related papers: Tunnel junctions on as-grown superconducting MgB2 …
In high-quality c-axis-oriented MgB2 thin films, we observed high critical current densities (Jc) of 16 MA/cm^2 at 15 K under self fields comparable to those of cuprate high-temperature superconductors. The extrapolated value of Jc at 5 K…
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…
Tunnel junctions are one of the key elements of chip-scale microsystems serving various technologies from classical microelectronics to quantum information. Aluminium and its oxide (AlOx) have dominated cryogenic tunnel junction technology…
We report the demonstration of dc and ac Josephson effects as well as tunneling spectroscopy measurements on Nb/Al2O3/Al/MgB2 thin films heterostructures. Data on dc Josephson effect suggest the presence of two characteristic critical…
The complex conductivity of a MgB2 film has been investigated in the frequency range 4 cm^{-1}< nu < 30 cm^{-1} and for temperatures 2.7 K < T <300 K. The overall temperature dependence of both components of the complex conductivity is…
Reproducible high-Tc Josephson junctions have been made in a rather simple two-step process using ion irradiation. A microbridge (1 to 5 ?m wide) is firstly designed by ion irradiating a c-axis-oriented YBa2Cu3O7-? film through a gold mask…
The MgB2 superconductor synthesized in a flowing argon atmosphere using nanometer magnesium powder as the raw materials, denoted as Nano-MgB2, has been studied by the technique of in-situ high temperature resistance measurement (HT-RT…
The discovery of superconductivity at 39 K in magnesium diboride offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. With twice the critical temperature of…
Break junctions made of the optimally doped high temperature superconductor Bi2Sr2Ca2CuO8 with Tc of 90 K has been investigated in magnetic fields up to 12 T, at temperatures from 4.2 K to Tc. The junction resistance varied between 1kOhm…
We report enhanced two-component superconductivity in (CoSi2/Si)/TiSi2 superconductor/normal-metal (S/N) heterojunctions. An enhanced superconducting transition temperature about twice that of CoSi2 and an upper critical field about 20…
We observe proximity-induced superconductivity in the \textit{in situ} prepared heterostructures constructed by topological insulator Bi$_{2}$Te$_{3}$ thin films and high-temperature cuprate superconductors…
We have observed that submicron sized Al--AlO{$_x$}--Al tunnel junctions can be stabilized completely by annealing them in vacuum at temperatures between $350^{\circ}$C and $450^{\circ}$C. In addition, low temperature characterization of…
MgB2 thin films were cold-grown on sapphire substrates by pulsed laser deposition (PLD), followed by post-annealing in mixed, reducing gas, Mg-rich, Zr gettered, environments. The films had Tcs in the range 29 K to 34 K, Jcs (20K, H=0) in…
We report the growth, characterization and superconducting properties of a new amorphous superconductor, RexZr ( x ~ 6 ), in thin film form. Films were grown by pulsed laser deposition with the substrate kept at room temperature. Films with…
Conventional electron beam lithography has been used to fabricate mesoscopic Nb wires with a superconducting transition temperature above 7.0 K. The typical line width and the thickness were 200 nm and 45 nm respectively. Nb was deposited…
High superconducting transition temperature is favorable for the applications of superconductors. Some cuprate superconductors have the transition temperatures above 100 K, such as the Hg- or Tl-based 1223 and 1234 phases, but many of them…
We report on the preparation and the physical properties of superconducting (TaNb)_1-x(ZrHfTi)_x high-entropy alloy films. The films were prepared by means of magnetron sputtering at room temperature, with x ranging from 0 to 1 with an…
Bulk samples of MgB2 have been formed by hot isostatic pressing (HIPping) of commercial powder at 100MPa and 950=B0C. The resulting material is 100% dense with a sharp superconducting transition at 37.5K. Microstructural studies have…
Nanocrystalline MgB$_2$ produced by mechanical alloying has been shown to exhibit enhanced superconducting properties such as increased pinning and higher critical currents. However, the effects of the synthesis process on the intrinsic…
Epitaxial MgB2 thick films were grown on Al2O3 substrates at 600 oC by using the hybrid physical chemical vapor deposition (HPCVD) technique. In order to obtain a high magnesium vapor pressure around the substrates, we used a special…