YBa2Cu3O7−x (YBCO) coated conductors are realized by the deposition of a YBCO film atop thin (10−6 m) ceramic buffer layers, previously deposited upon a high resistance nickel alloy. On the other side of the tape a copper layer is often added to create an alternative current path during quenches. Several investigations have shown a different qualitative behaviour of the voltages measured on the...

A comprehensive study of the dc and rf electrodynamic properties of YBa 2 Cu 307-, (YBCO) thin films, grain boundaries and Josephson junctions (JJ) is presented. The surface impedance Z, = R, + iX, of YBCO thin films is shown to have a dependence on rf current, which leads to nonlinear power losses at levels of rf power that are relevant for device applications. To understand the loss mechanism...

Doping of YBa2Cu3O7-δ (YBCO) has become an effective means of increasing the flux pinning and critical current densities (Jc) in thin film superconductors, while maintaining the transition temperature (Tc). In previous research efforts, our group showed that doping (Y1xREx)BCO with typically deleterious rare earth (RE) elements can be used to improve the film’s current density via flux pinning ...

YBCO thin films have been grown by Metal Organic Chemical Vapour Deposition in ;I cold wall type reactor. The 0-diketonates of yttrium, barium and copper are used as precursors. Filrna have bcen deposited on (001 I MgO and (012) LaA103 single crystalline substrates. The morphology is very dependant on thc gas p h a x composition. Different oxygen partial pressures have been investigated. An inc...

We have implemented coherent gradient sensing (CGS) as an in-situ diagnostic in an MOCVD reactor to measure curvature and changes in curvature with varying temperature and O2 partial pressure on thin ̄lm YBCO on MgO (001) substrates. CGS is a novel, real-time, full̄eld optical technique that provides a direct map of the components of the curvature tensor across the surface of the wafer. We have ...

Nanoparticles of BaSnO3 were incorporated into YBa2Cu3O7−x (YBCO) films on LaAlO3 substrates for magnetic flux pinning enhancements. More than an order of magnitude improvement in the high field magnetization Jc at 6 T at 77 K was observed as compared to regular YBCO films. The irreversibility field (Hirr) was increased to 8.5 T at 77 K and to 13.4 T at 65 K. The in-field transport current meas...

Broken time reversal symmetry (BTRS) in d wave superconductors is studied and is shown to yield current carrying surface states. The corresponding spontaneous magnetization is temperature independent near the critical temperature Tc for weak BTRS, in accord with recent data. The Hall conductance is found to vanish at zero wavevector q and finite frequency ω, however at finite q, ω it has an unu...

Significant improvement of the signal-to-noise ratio (SNR for magnetic resonance imaging (MRI) applications, in which the thermal noise of the rf receiver probe dominates the system noise can be achieved by cooling down a normal metal probe or by using superconductors. In this work, the SNR enhancement expected from using superconductors for single coil and/or phased array designs are calculate...

Spin-pumping across ferromagnet/superconductor (F/S) interfaces has attracted much attention lately. Yet the focus been mainly on s-wave superconductors-based systems whereas (high-temperature) d-wave superconductors such as YBa2Cu3O7-d (YBCO) have received scarce despite their fundamental and technological interest. Here we use wideband ferromagnetic resonance to study spin-pumping effects in ...