抄録
Since the discovery of the new high Tc superconductor, various kinds of film growth technique have been reported on fabrication of an oxide superconducting film, especially YBCO and BSCCO above liquid nitrogen temperature. All of the techniques require the so-called post-growth heat treatment or a heating of the substrate during the deposition in order to grow an adequate polycrystal which can realize the superconducting state in the oxide. Such a heating process, however, yields some intermediate products at a boundary layer between the starting materials and the substrate, and the products result in degradation of the superconducting property.
In this paper, the annealing effect on the growth of YBCO or BSCCO oxide superconducting film and the substrate is investigated by using EDX analysis and SEM examination. In order to enhance the annealing effect, relatively thin YBCO and BSCCO films are fabricated with the starting materials pasted on substrates, and used rather than sputtered thin films for the analysis. MgO, Al2O3, SrTiO3, 5% or 8% Y stabilized ZrO2 (YTZ or YSZ) and so on are chosen as a substrate.
The results show that the heat treatment yields Ba compounds between YBCO and the substrates and Sr and Bi compounds between BSCCO and the substrates. Since the produced boundary layer of the intermediate product is the thinnest, MgO substrate can be recommended for YBCO film, and SrTiO3 substrate for BSCCO film.
