In situ high rate growth of high temperature superconductor tapes

In situ high rate growth of YBa₂Cu₃O_7-δ superconducting films has been carried out using e-beam deposition. A deposition flux controller was developed to monitor and control the deposition rates using tunable diode, laser-based, atomic absorption. A wide range of temperatures, deposition rates, and oxygen fluxes including atomic, molecular oxygen, have been explored in order to understand both kinetic and thermodynamic stability. Critical current density above 1 MA/cm² has been achieved on SrTiO₃ substrate samples with growth rates up to 75 Å/sec. Samples prepared on IBAD YSZ/Ni tapes exhibit similar resistivity properties and x-ray diffraction patterns. However, critical current densities of the tapes are around 5 kA/cm² or lower. The poor critical current density of the tape is attributed to interactions between the YBa₂ Cu₃O_7-δ film and the YSZ buffer layer