Magnetic-field dependence of the microwave surface resistance in MgB2 and Ba(06)K(0.4)BiO(3) samples

Microwave response of coaxial cavities made of bulk MgB2

Microwave properties of Ba(0.6)K(0.4)BiO(3) crystals

We report on field-induced variations of the microwave surface resistance at 9.6 GHz of Ba(0.6)K(0.4)BiO(3) crystals. Energy losses have been investigated as a function of the static magnetic field in the range of temperatures 4.2 K - Tc. By analyzing the experimental results in the framework of the Coffey and Clem model we determine the temperature dependence of the first-penetration field, upper critical field and depinning frequency. The results show that the pinning energy of this bismuthate superconductor is weaker than those of cuprates.

Effects of Weak Links in the Nonlinear Microwave Response of Bulk MgB2

Enhancing the luminescence efficiency of silicon-nanocrystals by interaction with H+ions

The emission of silicon nanocrystals (Si-NCs), synthesized by pulsed laser ablation in water, was investigated on varying the pH of the solution. These samples emit μs decaying orange photoluminescence (PL) associated with radiative recombination of quantum-confined excitons. Time-resolved spectra reveal that both the PL intensity and the lifetime increase by a factor of ∼20 when the pH decreases from 10 to 1 thus indicating that the emission quantum efficiency increases by inhibiting nonradiative decay rates. Infrared (IR) absorption and electron paramagnetic resonance (EPR) experiments allow addressing the origin of defects on which the excitons nonradiatively recombine. The linear correl…

Magnetic Field Dependence of Microwave Surface Resistance in MgB2

Microwave response of a cylindrical cavity made of bulk MgB2 superconductor

Isteresi magnetica della resistenza superficiale a microonde nel superconduttore Nb

Microwave response of bulk MgB2 samples of different granulariry

Microwave Surface Resistance of High-Tc Superconductors near Liquid Nitrogen Temperature

Proprietà e applicazioni a microonde del MgB2

Critical-state effects on the microwave surface resistance of superconductors

Anomalous hysteretic behaviour of the microwave surface resistance in MgB2 superconductor

Microwave Characterization of High Density Bulk MgB2 for Microwave Resonant Cavity Design

Dipendenza dal campo magnetico della resistenza superficiale a microonde in MgB2

Resistenza superficiale a microonde nel superconduttore MgB2

Surface-Barrier Effects in the Microwave Second Order Response of Superconductors

FIELD-INDUCED VARIATIONS OF THE MICROWAVE SURFACE RESISTANCE IN MgB(2) AND Ba(0.6)K(0.4)BiO(3) SAMPLES

Microwave Second-Harmonic Emission in MgB2 Superconductor near Tc

A microwave cylindrical cavity made of bulk MgB2 superconductor produced by reactive liquid Mg infiltration process

Microwave Response of Coaxial Cavities Made of Bulk Magnesium Diboride

We report on the microwave (mw) properties of coaxial cavities built by using bulk MgB2 superconductor prepared by reactive liquid Mg infiltration technology. We have assembled a homogeneous cavity, by using an outer MgB2 cylinder and an inner MgB2 rod, and a hybrid cavity by using an outer copper cylinder and the same MgB2 rod as inner conductor. By the analysis of the resonance curves, in the different resonant modes, we have determined the microwave surface resistance, Rs, of the MgB2 materials as a function of the temperature and the frequency, in the absence of DC magnetic fields. At T = 4.2 K and f = 2.5 GHz, by a mw pulsed technique, we have determined the quality factor of the homog…

Microwave Harmonic Emission in MgB2 Superconductors