OCT 01, 2000
Stacking layers of pure and calcium‐doped YBa2Cu3O7−δ increases the coupling between the superconducting grains without sacrificing the transition temperature.
Superconducting wire is a central part of many of the applications devised for high‐temperature superconductors in the 15 years following their discovery. With transition temperatures above the boiling temperature of liquid nitrogen (77 K), these superconductors have the potential to provide cheap, low‐loss wires capable of carrying large currents. The technological realization of this potential has been difficult, however, due in part to the anisotropic character of the ceramic high‐ materials. Although single crystals of high‐ superconductors have high critical current densities—the figure of merit in wire applications—polycrystalline wires suffer from significantly reduced current‐carrying ability.
© 2000. American Institute of Physics