Heavy Ion Irradiation of Bi-2223 Silver-Clad Tapes for Superconducting Current Density Enhancement

Silver-clad composite tapes of 13i(Pb)SrCaCuO-2223 were irradiated with 1 GeV Au23+ ions perpendicular to the tape plane, creating columnar tracks with 10 nm diameter. Detailed transmission electron microscopy shows continuous columns, but with variations in the track thickness of +/− 2 nm. Magnetic hysteresis measurements show substantial enhancements of superconducting current density at most temperatures and fields. Granular and nongranular models for the origin of the magnetic signals are discussed. The results indicate the potential for further performance improvement in high-temperature superconducting wire technology, as well as limits in the high-field performance at 77 K.