Abstract
A new high-T c superconducting cuprate composed of Ba, Cu and O was prepared on SrTiO3(001) substrate by reactive coevaporation. The superconducting phase is formed only in the limited temperature range between 575 and 625° C and in a narrow compositional range. Observations of the X-ray diffraction and transmission electron microscopy suggests that the superconducting phase is the 214-based structure. Superconductivity is obtained only after strong oxidation after film growth. The resistivity measurement shows T c onset≈60 to 70 K and T c end≤38 K and the magnetic measurement shows T c onset≈85 to 90 K.