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A study of the switching of YBCO thin film resistive fault current limiting devices is presented. The study was conducted on 300-nm thick films of the high temperature superconductor that were deposited on 2 inch and 4 inch sapphire substrates via the thermal co-evaporation method. The highest destruction free switching power was measured at 57 kVA while the highest switching power density achieved by the experiment was 2.5 kVA/cm2, the highest value ever reported for switching power densities.

The biaxial alignment of textured, Y2O3 stabilized ZrO2 (YSZ) buffer layers and large-area YBCO films on polycrystalline substrates was examined through X-ray diffraction. Findings show that the in-plane alignment of the YSZ buffer layer is at 14 to 18 degrees while YBCO exhibits a better alignment of seven to nine degrees. It also was noted that the difference of the alignment of the YSZ and YBCO is proportional to the alignment of the YSZ buffer layer.

High quality YBCO films on metal tapes with biaxially aligned MgO buffer layers were successfully deposited. For the deposition of the buffer layers, e-gun evaporation on inclined substrates with a very high deposition rate of up to 250 nm/min was used. The MgO layers were biaxially textured with an in plane full width at half maximum of 8 degrees. Reactive thermal co-evaporation was used to deposit YBCO films on ISD buffer layers. The tilt of the (001)-axis caused the anisotropy of the critical current density of the films.

A study was conducted on the radio frequency power dependence of large area YBCO thin films on LaAlO3 substrates. A coplanar waveguide resonator method was employed in determining the changes of inductance and loss vs circulating microwave currents. Correlations were observed between the radio frequency power dependence and penetration depth, crystal structures and other film properties.

A thermal co-evaporation system was used for continuous YBa2Cu3O7-delta film deposition on large areas. Individual metal fluxes were measured through an atomic absorption spectroscopy-based optical rate control system. Results reveal that in situ reloading of metal resources at long time is possible. The grown films also exhibited excellent superconducting properties as compared to films developed using a standard co-evaporation system.

Reactive thermal co-evaporation may be employed in high quality YBa2Cu3O7 thin film fabrication. Double sided homogeneous films maybe deposited on substrate areas up to 9 inches in diameter by combining the approach with a rotating disk heater. The homogeneity of critical current densities was monitored through a scanning inductive probe. The approach was successfully tested for Nd1-xBa2+xCu3O7 films.

YBCO air-bridge microbolometers are fabricated by depositing high temperature superconductive YBCO thin films on silicon substrates using silicon micromachining. The bolometers have a gain ratio which is one order of magnitude higher than that of conventional bolometers. They also have time constants as low as 81 microseconds and are phonon noise limited. These features make the bolometers suitable for infrared imaging applications.

A 4-bit instantaneous frequency meter (IFM) with a frequency range of 9.5-10.5 GHz is integrated with coplanar YBCO delay lines on a LaAlO3 wafer to create a compact, light size microwave receiver. The integration of the IFM and the delay lines on a single substrate minimizes the circuit's insertion loss and allows greater flexibility in the circuit design. The receiver has a maximum delay of 4.0 nanoseconds.

The thermal reactive co-evaporation technique was used to grow single-sided and double-sided YBa2Cu3O7 films on substrates with diameters of up to four inches. The process was implemented using LaAlO3, yttrium-stabilized zirconia, magnesium oxide, sapphire, silicon and gallium arsenide substrates. To date, it has yielded homogeneous films with critical temperatures above 86 K and critical current densities of more than 2,000,000 A/cm2.

The characterization of Ba(1-x)KxBiO3 thin films grown on different substrates by the thermal co-evaporation of potassium, barium and bismuth was carried out. All films were epitaxially optimized via the deposition of a BaBiO3 seed layer prior to film growth. In contrast to films grown on SrTiO3 substrates, a PrBa2Cu3O7 buffer layer was used in films deposited on magnesium oxide, CeO2 buffered sapphire, yttria-stabilized zirconia (YSZ) and YSZ buffered silicon substrates.

The growth of superconducting thin films on a semiconductor substrate is hampered by problems related to the large differential thermal expansion between film and substrate that leads to film fracture. To prove that film cracking may be reduced, YBa2Cu3O(7-delta) films were deposited on silicon and gallium arsenide substrates using magnesium oxygen buffer layers for the latter. The results indicate the need for suitable wafer encapsulation for films grown on gallium arsenide/magnesium oxygen.

Investigating YBa2Cu3O(sub 7-x) thin films deposited on substrates up to 20 cm x 20 cm using thermal reactive co-evaporation with a linear reciprocating oxygen pocket is discussed. Moving the substrate leads to a homogeneous stoichiometry and therefore uniform superconducting properties over the substrate area is shown.

Examines the ultrahigh frequency measurements of magnetic penetration and surface impedance of superconductor microstiplines on silicon and gallium arsenide substrates. Use of electro-optical sampling in detecting electrical pulses launched into superconducting striplines; Experimental details; Measurements and discussion.