PRODUCTION OF THIN FILM SUPERCONDUCTOR

PURPOSE:To obtain a thin film superconductor having improved industrial value with high reproducibility by depositing a thin film contg. Tl and O2 to a substrate, depositing then a thin film contg. Cu, an alkaline earth element of the group IIa, etc., and O2, then heat-treating in O2 gas atmosphere. CONSTITUTION:A thin Tl-O film 12 is deposited to about 0.2mum thickness on a single crystal (such as MgO) substrate 11 by the high frequency planar magnetron sputtering process, etc. Further, a thin film 13 contg. Cu, alkaline earth element of the group IIa (e.g., at least one kind among Ca, Sr or Ba), and O2 is deposited on the thin film 12 by sputtering to about 1mum thickness wherein molar ratios of elements of the thin films 12, 13 are adjusted to correspond to the molar ratios of elements to Tl in the formula (wherein A is Sr, Ba). A substrate 11 having been deposited with the thin films 12, 13 is then heat- treated at 700-950 deg.C for 1min-1hr, forming thus a thin Tl-Ca-Ba-Cu-O film 14. Thus, a thin film superconductor is obtd.