Bi–Sr–Ca–Cu–O superconducting films fabricated using metal alkoxides

Abstract

Superconducting films in the Bi–Sr–Ca–Cu–O systems were made using metal alkoxides. To prepare a dip-coating solution using a mixed alkoxide solution, insoluble Cu and Bi alkoxides were dissolved by modification with 2-dimethylaminoethanol and formation of a double alkoxide, respectively. Formation of the double alkoxides of Bi with Ca or Sr was confirmed using FT-IR and 1H-NMR. Bi–Sr–Ca–Cu–O films on yttria-stabilized ZrO2 and single crystal MgO(100) substrates were made using this solution. The films were closely oriented along the c-axis perpendicular to the substrate. The film on MgO(100) fired at 850 °C for 48 h showed two resistance drops around 115 and 85 K, corresponding to the high-Tc and low-Tc phases, respectively, and zero resistance at 72 K.