Flux Pinning and Properties of Solid-Solution (Y,Nd)1+XBa2-x Cu3O7-delta Superconductors Processed in Air and Partial Oxygen Atmospheres (Preprint)
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
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The effect of chemical composition substitutions on the flux pinning and physical properties of Y,Nd 1 XBalpha2-xCu3O7-gamma superconductors was studied in powders processed by solid-state reaction and equilibrated in air at 910 deg C. The powders were subsequently processed in 1 O2 atmosphere at 920 deg C to increased the superconducting transition temperature T sub c and critical current density J sub c. After processing in air, the powders were nearly pure single-phase compositions as determined by X-ray diffraction. Powders were finally annealed in 100 O2 atmosphere at temperatures 500 deg C to maximize Tsub c. The Tsub cs of the powders were measured by ac susceptibility and dc magnetization methods. Annealing powders with a final step in 1 O2 atmosphere compared to processing in air significantly enhanced Tsub c from 65-90 K to 92 K for all compositions tested, and also increased from about 1000 - 100,000 Asq cm to approximately 10exp 6 Asq cm. The flux pinning properties varied depending on exact composition, and the intrinsic behaviors changed with the final 1 O2 annealing treatment.
- Ceramics, Refractories and Glass
- Electricity and Magnetism
- Laminates and Composite Materials