RARE-EARTH BARIUM STANNATES - SYNTHESIS, CHARACTERIZATION, AND POTENTIAL USE AS SUBSTRATES FOR YBA2CU3O7-DELTA SUPERCONDUCTOR

A new group of complex perovskites, REBa(2)SnO(5.5) (where RE = Pr, Sm , Eu, and Gd) have been synthesized and sintered as single-phase mater ials with high sintered density and stability by the solid-state react ion method. The structure of REBa(2)SnO(5.5) was studied by the X-ray diffraction technique, and all of them were found to be isostructural and have a cubic perovskite structure, The dielectric constant and los s factor values of these materials are in a range suitable for substra te applications, The X-ray diffraction and resistivity measurements ha ve shown that there is no detectable reaction between YBa2Cu3O7-delta and REBa(2)SnO(5.5), even when the substances are mixed thoroughly and sintered at 950 degrees C for 15 h, Thick films of YBa2Cu3O7-delta fa bricated on polycrystalline REBa(2)SnO(5.5) substrates gave supercondu cting zero resistivity transition T-C(0) = 92 K, indicating the suitab ility of these new materials as substrates for YBa2Cu3O7-delta films.