Bi(2223) thick films (T-C(0)=109k) on Ba2GdNbO6: A new perovskite ceramic substrate for BSCCO superconductor

Ba2GdNbO6 has been developed as a new substrate suitable for the BSCCO supe rconductor. Ba2GdNbO6 has a complex cubic perovskite (A(2)BB'O-6) structure with a lattice constant a = 8.587 Angstrom. The DTA studies revealed that there is no phase transition occurring in Ba2GdNbO6 in the temperature rang e of 30-1300 degrees C. The thermal expansion coefficient of Ba2GdNbO6 is f ound to be 7.913 x 10(-6)degrees C-1 The dielectric constant and loss facto r of Ba2GdNbO6 are in a range suitable for its use as a substrate For micro wave applications. The Bi(2223) superconductor does not show any detectable chemical reaction with Ba2GdNbO6 even under extreme processing conditions. The thick films of Bi(2223) dip-coated on polycrystalline Ba2GdNbO6 substr ate gave a T-c(0) of 109 K and a current density of approximately 4 x 10(3) A/cm(2) at 77 K and zero magnetic field. (C) 1998 Published by Elsevier Sc ience Ltd. All rights reserved.