Chemical solution processing of Gd2Zr2O7 (GZO) thin films via sol-gel and metalorganic decomposition (MOD) precursor routes have been studied on textured Ni-based tape substrates. Even though films processed by both techniques showed similar property characteristics, the MOD-derived samples developed a high degree of texture alignment at significantly lower temperatures. Both precursor chemistries resulted in exceptionally dense, pore-free, and smooth microstructures, reflected in the cross-sectional and plan-view high-resolution scanning and transmission electron microscopy studies. On the MOD GZO buffered Ni–3at.% W (Ni–W) substrates with additional CeO2/YSZ sputtered over layers, a 0.8-μm-thick YBa2Cu3O7−δ (YBCO) film, grown by an ex situ metalorganic trifluoroacetate precursor method, yielded critical current, Ic (77 K, self-field), of 100 A/cm width. Furthermore, using pulsed-laser deposited YBCO films, a zero-field superconducting critical current density, Jc (77 K), of 1 × 106 A/cm2 was demonstrated on an all-solution, simplified CeO2(MOD)/GZO(MOD)/Ni–W architecture. The present study establishes GZO buffers as a candidate material for low-cost, all-solution coated conductor fabrication.

A controlled introduction of second-phase Y2BaCuO5 (211) nanoparticles into YBa2Cu3O7−δ (123) thin films was achieved for the first time for the purpose of increasing flux pinning. The island-growth mode of 211 on 123 was utilized to obtain an area particle density >1011 cm-2 of 211 thick-disk-shaped nanoparticles in individual layers. Composite layered structures of (211y nanoparticles/123z)×N were deposited by pulsed laser deposition on LaAlO3 substrates, with N bilayers = 24 to 100, y thickness = 1 to 2 nm, and z thickness = 6 to 15 nm (assuming continuous layer coverage). With 211 addition, the critical current densities at 77 K were higher at magnetic fields as low as 0.1 T and increased as much as approximately 300% at 1.5 T. The superconducting transition temperature was reduced by approximately 2 to 4 K for 211 volume fraction <20%. Reinitiation of 123 growth after every 211 layer resulted in a smooth and flat surface finish on the films and also greatly reduced surface particulate formation especially in thicker films (∼ μm).

Partial-melt processing of Bi2+xSr2-x-yCa1+yCu2O8+δ (Bi-2212) thick-film conductors with additions of nanophase Al2O3 was studied for dual purposes of increasing flux pinning and inhibiting Sr—Ca—Cu—O phase defect formation. Nanophase Al2O3 (<50% mole fraction) was added to Bi:Sr:Ca:Cu:O powders with four different compositions: three with Bi:Cu approximately 2:2 and one (Bi2Sr2.38Ca1.15Cu2.92O9.7+δ) closer to the ideal Bi-2223 composition. The effect of Al2O3 addition on film microstructural and superconducting properties was studied for a range of partial-melt temperatures (865 to 900 °C). Results were compared to Al2O3-free films with compositions lying within the single-phase solid-solution 2212 region. Nanophase Al2O3 reacted with 2212-type precursors to form a composite of micron size or smaller particles of solid-solution (Sr,Ca)3Al2O6 in a solid-solution 2212 superconducting matrix. The Ca content of the (Sr,Ca)3Al2O6 particles formed approximated that of the 2212 precursor (≤6% mole fraction difference). Addition of 6–25% volume fraction of (Sr,Ca)3Al2O6 to Bi-2212 (by reaction between Al2O3 and Bi-2212) only slightly reduced superconducting transition temperatures and c-axis texturing; however this addition improved film quality by reducing Sr—Ca—Cu—O defect volume fraction by factors of 2 to 6 and significantly increased the critical current density by over one order of magnitude for 0 to 2 T applied fields at 20 to 30 K.

Mechanical bending of HTS tapes can result in the deterioration and destruction of their transport properties. Depending on the magnitude and type of strain (tensile or compressive), the films can be permanently damaged by fracture and recoverable only by post heat treatment, or simply elastically strained with recoverable transport properties upon release of the strain. Here we present results of strain effects on BSCCO (2212) /Ag tape transport properties and post heat treatment recovery of those properties.

A nitrate solution of Y, Ba and Cu was atomized and introduced into an inductively coupled argon ‐ oxygen plasma operated at 4.4 kW and 13.56 MHz under atmospheric pressure. As‐deposited superconducting films were grown on (100) YSZ substrates heated to 650°C. Critical temperatures of 85 K and critical current densities of 7.0 x 104 amp/cm2 at 77 K have been achieved. X‐ray diffraction shows the films to be oriented with the c‐axis perpendicular to the substrate surface. The effects of process parameters, solution composition, and aerosol concentration on the superconducting properties and microstructures will be discussed.

A new mode of precipitation of the metastable Al3 Zr in Al-Zr-alloys has been investigated. The salient aspects of this precipitation reaction are: (i) The formation of precipitate configurations of a well defined macroscopic morphology, (ii) Each individual precipitate within the colonies grows in crystallographic directions, and (iii) The absence of a high angle grain boundary as a reaction front.