Growth characteristics of ZrO2 insulation coatings on Ag/AgMg sheathed Bi-2212 superconducting tapes

We have investigated the growth behaviors of high temperature compatible ZrO2 insulation coatings on Ag and AgMg sheathed Bi2Sr2Ca, Cu2Ox superconducting tapes depending on number of dipping and thermal conditions. The coatings were fabricated on long-length superconducting tape substrates using a solution derived from Zr tetrabutoxide, solvent and chelating agent for high magnetic field magnets. The layer-on-layer growth behaviors were characterized by environmental scanning electron microscope (ESEM), energy dispersive spectroscopy (EDS). X-ray maps and X-ray diffraction (XRD). This research showed that the ZrO2 coatings were regularly grown on Ag-based tape substrates and coating thickness increased with increasing number of dipping. It was found that ceramic oxides formed at temperature range 450 and 550 degreesC. The final coating thickness changed between 6 and 8 mum after annealing process. Resistance of insulation measured from surface and edge regions of the coatings were 14.06 and 13.95 MOmega, respectively. Critical current (I-c) of ZrO2/AgMg/Bi-2212 coils was found to be 110.9 A at 4.2 K using the 10(-4) V/m criterion and in a background magnetic field of 19.2 T. (C) 2003 Elsevier B.V. All rights reserved