We present results of AC and DC magnetic moment measurements on a Pb(50 nm)/Cu(10 nm) bilayer film with a triangular antidot lattice of spacing 866 nm and diameter 350 nm. The sharp peaking of matching anomalies in the AC and DC magnetization curves indicates a proximity coupling of the Pb and Cu layers, which is also supported by an asymmetric splitting of matching peaks in AC moment data. Thi...

The thickness dependence of the superconducting energy gap ΔLa of double hexagonally close packed (dhcp) lanthanum islands grown on W(110) is studied by scanning tunneling spectroscopy, from the bulk to the thin-film limit. Superconductivity is suppressed by the boundary conditions for the superconducting wavefunction on the surface and W/La interface, leading to a linear decrease of the critic...

Vortex lattice dynamics has been studied in thin Nb superconducting films sputtered on top of a dense triangular array of V dots with and without an intermediate SiO2 insulating layer. While the insulating layer modifies only slightly the Nb film corrugation, it reduces superconducting commensurability effects (CE) substantially. This implies that superconducting commensurability is dominated b...

As the normal state sheet resistance, Rn, of a thin film superconductor increases, its superconducting properties degrade. For Rn ≃ h/4e superconductivity disappears and a transition to a nonsuperconducting state occurs. We present electron tunneling and transport measurements on ultrathin, homogeneously disordered superconducting films in the vicinity of this transition. The data provide stron...

In contrast to its bulk crystal, the FeSe thin film or layer exhibits better superconductivity performance, which recently attracted much interest in its fundamental research as well as in potential applications around the world. In the present work, tuning superconductivity in FeSe thin films was achieved by magnesium-doping technique. Tc is significantly enhanced from 10.7 K in pure FeSe film...

We report the structural and superconducting properties of FeSe0.3Te0.7 (FST) thin films with different thicknesses grown on ferroelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 substrates. It was shown that the FST films undergo biaxial tensile strains which are fully relaxed for films with thicknesses above 200 nm. Electrical transport measurements reveal that the ultrathin films exhibit an insulating beha...

Two atomic layers of Ni condensed onto Pb films behave, according to anomalous Hall effect measurements, as magnetic dead layers. However, the Ni lowers the superconducting Tc of the Pb film. This has lead to the conclusion that the Ni layers are still very weakly magnetic. In the present paper the electron dephasing due to the Ni has been measured by weak localization. The dephasing is smaller...

The nonlocal resistivity in fluctuation region of thin superconducting films is observed and investigated. It is supposed that the observed non-local resistivity is caused by a difference of distribution laws of normal and superconducting current density. The measurements show that the nonlocal resistivity is suppressed in low magnetic field. The obtained results are interpreted as the absence ...

Bulk niobium Superconducting Radio-Frequency cavities are a leading accelerator technology. Their performance is limited by the cavity loss and maximum acceleration gradient, which are negatively affected by vortex penetration into the superconductor when the peak magnetic field at the cavity wall surface exceeds the vortex penetration field (Hvp). It has been proposed that coating the inner wa...