HIGH-QUALITY SUPERCONDUCTING THIN-FILMS OF BI2SR2CA2CU3OX GROWN INSITU BY METALORGANIC CVD

THE superconducting copper oxide system Bi-Sr-Ca-Cu-O (BSCCO) has attracted much attention owing to its high transition temperatures T(c) and its stability on exposure to air, relative to the corresponding properties of the Y-Ba-Cu-O system. But despite intense effort, growth techniques capable of yielding as-deposited films with high T(c) and high critical current density, J(c), have not yet been forthcoming. Here we report the preparation and properties of c-axis-oriented single-phase Bi2Sr2Ca2Cu3O(x) films grown in situ without post-annealing by metalorganic chemical vapour deposition (MOCVD). Our films have the highest T(c) and J(c) at 77 K reported so far for BSCCO films grown in situ; one film had a zero-resistance T(c) of 97 K, and a J(c) of 3.8 x 10(5) A cm-2 at 77 K in zero magnetic field. This film showed little degradation of J(c) in magnetic fields of up to 8 T applied parallel to the crystallographic a-b plane. The magnetic-field dependence of J(c) and observed surface morphologies strongly suggest that these as-grown films have no weak links, which is a promising characteristic for device applications.