STUDY OF HALOGEN DOPING IN POLYCRYSTALLINE YBA2CU3O7-DELTA

This paper presents systematically the doping effects of halogens in YBa2Cu3O7-delta polycrystalline samples, with a series of concentrations of fluorine, chlorine, bromine or iodine. All samples were prepared by chemical method of citrate pyrolysis, which makes the halogen concentration in the samples more uniform. Samples doped with F have T(c) as high as 94.5 K, Cl, Br and I dopings also raise T(c) to a certain extent. In addition, the influence of halogen doping on critical current density, morphology, constitution and so forth is discussed.