SYNTHESIS AND CHARACTERIZATION OF RARE-EARTH BARIUM ANTIMONATES, A NEW GROUP OF COMPLEX PEROVSKITES SUITABLE AS SUBSTRATES FOR YBA2CU3O7-DELTA FILMS

A new group of complex perovskites, REBa(2)SbO(6) (where RE = Pr, Sm, and Gd), have been synthesized and sintered as single phase materials by the solid state reaction method. These materials are found to be is ostructural and to have a complex cubic perovskite structure. X-ray di ffraction and resistivity measurements have shown that there is no det ectable chemical reaction between YBa2Cu3O7-delta and REBa(2)SbO(6) ev en under severe heat treatment at 950 degrees C and that the addition of REBa(2)SbO(6) up to 20 vol% in YBa2Cu3O7-delta shows no detrimental effect on the superconducting properties of YBa2Cu3O7-delta. The diel ectric constant and loss factor values of the sintered REBa(2)SbO(6) m aterials are in a range suitable for their use as substrates for micro wave applications. Thick films of YBa(2)Cu3O(7-delta) fabricated on po lycrystalline REBa(2)SbO(6) substrates give superconducting zero resis tivity transition temperature T-c(0) = 92 K, indicating the suitabilit y of these materials as substrates for YBa2Cu3O7-delta films. (C) 1995 Academic Press, Inc.