Fabrication of Gd–Ba–Cu–O films by the metal–organic deposition method using trifluoroacetates

Abstract

We have fabricated Gd–Ba–Cu–O (GdBCO) films on LaAlO3 single crystalline substrates by a metal–organic deposition method using trifluoroacetates (TFAs). The highest value of the critical temperature of superconductivity (Tc) of these TFA-derived GdBCO films was 92.9 K and the critical current density (Jc) reached 2.9 MA cm−2 at 77 K in the self-field. While this value of Jc is smaller than that of a previously reported Y–Ba–Cu–O (YBCO) film prepared by the same technique, the critical current density at large magnetic field surpassed that of the YBCO film. The Tc of the present GdBCO films depended only weakly on the crystallization temperature and the partial pressure of oxygen (pO2) for the range of parameters investigated in the present study. On the other hand, Jc was found to vary largely with the processing conditions. We discuss the reason for this strong processing parameter dependence of Jc by summarizing our results on a pO2 versus temperature diagram.