Versatile new metalorganic process for preparing superconducting thin films

Abstract

A new technique for producing thin films of the high-temperature perovskite superconductors, LnBa2Cu3O7−x, where Ln represents a rare-earth element, using spin-on metalorganic precursors is described. Pyrolysis of the spin-coated films, consisting of mixed metal (2-ethyl hexanoates), leads to black films up to several microns thick whose degree of orientation is a function of the processing temperature and duration. Representative films of YBa2Cu3O7−x on MgO begin to exhibit orientation with the c axis perpendicular to the film plane at heat treatments above 900 °C. The superconducting behavior of a highly oriented film produced at 990 °C is characterized by Tc(onset)=89 K, Tc(R=0)=77 K, and Jc=103 A cm−2 at 65 K.