We report a large normal-state magnetoresistance with temperature-dependent anisotropy in very clean epitaxial MgB2 thin films (residual resistivity much smaller than 1 microOmega cm) grown by hybrid physical-chemical vapor deposition. The magnetoresistance shows a complex dependence on the orientation of the applied magnetic field, with a large magnetoresistance (Delta(rho)/(rho)0=136%) observ...

In this paper we compare the performance of MgB2 Hot-Electron Bolometer Mixers operating at Local Oscillator frequencies of 0.6 THz and 1.63 THz. The minimum noise temperatures that were obtained are 700 K and 1150 K for 0.6 THz and 1.63THz respectively. The receiver noise bandwidth is of the order of 2.2-3GHz for 10nm thick HEB devices with a Tc of 8.5K. Sub-micrometer size HEBs were also fabr...

MgB2 superconducting bulk materials have excellent potential for various applications. In this review, the characteristics and challenges of as a material, recent research trends, such synthesis dense bulks using high pressure process, atmospheric process liquid gas diffusion, are introduced.

The temperature dependence of the real part of the microwave complex conductivity at 17.9 GHz obtained from surface impedance measurements of two c-axis oriented MgB2 thin films reveals a pronounced maximum at a temperature around 0.6 times the critical temperature. Calculations in the frame of a two-band model based on Bardeen-Cooper-Schrieffer (BCS) theory suggest that this maximum correspond...

Superconducting transition temperatures (Tc’s) of MgB2, Mg1−xCaxB2, Mg1−xNaxB2, and Mg1−xAlxB2 are studied within the McMillan approximation using electronic and structural information obtained from density functional theory within the generalized gradient approximation. The density of states and Tc of MgB2 are both shown to be extremely sensitive to volume; in fact the density of states around...

We report on the microwave properties of a resonant cylindrical cavity made of bulk MgB2 superconductor, produced by the reactive liquid Mg infiltration process. The frequency response of the cavity has been measured in the range 5÷ 13 GHz. Among the various modes, the TE011, resonating at 9.79 GHz, exhibits the highest quality factor. For this mode, we have determined the temperature dependenc...

We present the fabrication and test results of Hot-Isostatic-Pressed (HIPed) Powder-in-Tube (PIT) MgB2 coils. The coils properties were measured by transport and magnetization at different applied fields (H) and temperatures (T ). The engineering critical current (Je) value is the largest reported in PIT MgB2 wires or tapes. At 25 K our champion 6-layer coil was able to generate a field of 1 T ...

Owing to the linguistic richness of Arabic language, which contains more than 6000 roots, building a reliable language model for speech recognition systems faces many challenges. This paper introduces free automatic system Modern Standard based on an end-to-end-based Deep Speech architecture developed by Mozilla. The proposed uses character-level sequence-to-sequence map character alignment pro...