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A ramp edge-geometry superconductor-normal-superconductor configuration was used to develop high-temperature superconducting Josephson junctions and direct current superconducting quantum interference devices. The electrodes used was Ag-doped YBa2Cu3O7-x and the barrier employed was PrBa2Cu3O7-x. The devices exhibited a voltage modulation of 37 micro V and a magnetic field noise of -2 pTHz(super 1/2) at 1 kHz.

The structural and electric properties of high temperature superconducting YBCO SNS Josephson junctions fabricated via unique normal-metal layer construction are investigated using current-voltage measurements, x-ray diffraction analysis and Rutherford backscattering spectrometry. Results show that the junctions have an N layer which consists of a gradient Pr:YBCO multilayer configuration. They also show excellent electrical properties above liquid nitrogen temperature.

The optimal conditions for off-axis magnetron sputtering of multilayered YBa2Cu3O(7-x) (YBCO) films on magnesium oxide substrates were investigated with the further aim of developing superconducting-normal-superconducting junctions. Among the deposition parameters evaluated were film nucleation temperature, substrate-target relationship and oxygen annealing period. Consequently, it was shown that a lower nucleation temperature enhances the crystallinity and in-plane orientation of the YBCO films.

The pulsed laser deposition of YBa2Cu3O(7-delta)/BaTiO3/YBa2Cu3O(7-delta) (YBCO) multilayers on silicon substrates buffered by yttrium-stabilized zirconia layers was studied as a means of fabricating epitaxial ferroelectric capacitors. The approach, which employed YBCO layers as metallic electrodes, yielded multilayer structures with a c-axis orientation normal to the substrate.

The multiple-zone flow-through thallination process has been successfully employed to fabricate smooth Tl2Ba2CaCu2O8 and TlBa2CaCu2O7 thin films on LaAlO3 substrates. The scalable process requires the use of Ba2CaCu2O5 precursor films, thallic oxide and oxygen or argon as the carrier gas. It yields Tl2Ba2CaCu2O8 films with inductive transition temperatures of 107.6 K, critical current densities of 130 kA/cm2 at 75 K and surface resistances of 1.3 milli-ohm at 10 GHz and 80 K.

The characterization of Nd1.85Ce0.15CuO(4-y) (NCCO) thin films epitaxially grown on sapphire substrates with a yttria-stabilized zirconia buffer layer was performed. This was carried out via x-ray diffraction and transmission electron microscopy techniques as well as microwave surface resistance measurements. Based on the results, a heterostructure consisting of an yttrium-barium-copper-oxide layer, a dielectric layer of SrTiO3 and an NCCO layer was prepared.

Ion beam assisted deposition is used to create textured yttria-stabilized-zirconia buffer layers on flexible nickel substrates prior to the preparation of high current YBa2Cu3O7-gamma thick films. This approach enables the formation of c-oriented thick films with strong in-plane textures. The films produced using this method also exhibit excellent resistance to high magnetic fields at cryogenic temperatures.

Studies on the superconducting and structural properties of Nd(sub 2-x)Ce(sub x)CuO(sub 4-y) films of varying thickness grown on several substrates reveal that the differences in superconducting properties result from film strains introduced by lattice mismatch and the charge imbalance at the interface. n-type SuFET structures built on fluorite-type substrates of YSZ are better superconductors than perovskite-type substrates.

A study was conducted on the surface topography of superconducting YBCO thin films. The films were prepared by pulsed laser deposition. Critical current densities observed in the YBCO thin films were found to be larger than those existing in bulk materials. Screw dislocations were also found to be either repulsive or atractive depending on the dominant pinning mechanism and also affected current densities. Frequent oxygen defects were attributed to flux pinning.