During the fabrication of niobium superconducting radio frequency (SRF) particle accelerator cavities procedures are used that chemically or mechanically remove the passivating surface film of niobium pentoxide (Nb2O5). Removal of this film will expose the underlying niobium metal and allow it to react with the processing environment. If these reactions produce hydrogen at sufficient concentrat...

We have studied niobium superconducting thin wires deposited onto a SrTiO3 substrate. By measuring the reflection coefficient of the wires, resonances are observed in the superconducting state in the 130 MHz to 4 GHz range. They are interpreted as standing wave resonances of one-dimensional plasma modes propagating along the superconducting wire. The experimental dispersion law, omega versus q,...

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We show the theoretical depairing current limit can be achieved in a robust fashion in highly ordered superconductor nanomesh films having spatial periodicities smaller than both the superconducting coherence length and the magnetic penetration depth. For a niobium nanomesh film with 34 nm spatial periodicity, the experimental critical current density is enhanced by more than 17 times over the ...

We report a study on the desorption properties, crystallography and chemical state of MgH2 and 1 mol% Nb2O5 ball-milled composites. Desorption temperatures of the composites decreased with increase of ball-milling time. Size of MgH2 crystallites decreased during ball-milling. Reduction of Nb2O5 after ball-milling was confirmed by tracing the chemical state of Nb and was further supported by TEM...

The analogy is explored between phase-slip in charge-density wave conductors, which brings about the growth and decay of an electronic crystal, and the processes of growth and plastic flow which occur in conventional crystals. The experimental data on NbSq are re-examined, and new measurements of the voltage Vps needed to produce phase-slip at a given rate presented. It is suggested that Vps is...

the series of mono-metallic and bi-metallic catalysts have been prepared by impregnatingwith solutions containing compound of h2ptc15,nbc15 and lml hc1 (0.1 mol). the activityand selectivity of the catalysts have been determined under conditions at 450-500°c, 15-30atm. molar ratio h2/c7h16=5 and vvh=1.5/h for converting n-heptane. under theseexperimental conditions it has been established that ...

Layered ternary chalcogenides AxMX2 (A = al­ kali metal, M = transition metal, X = S, Se) of group IV b to VI b elements may be prepared either by reactions a t high temperatures (600-1000 °C) from the elements1 and via alkali halide m elts2 or at low temperatures from the corresponding binary phases MX2 by intercalation of alkali metals from liquid ammonia3. Both series of compounds were found...