Effect of Phase Composition of Superconductor Y3Ba5Cu8O18+δ on Its Conducting Characteristics

The effect of the method of synthesis on the crystallographic parameters, electrical properties, and oxygen nonstoichiometry of superconducting cuprate with nominal composition Y3Ba5Cu8O18+δ was investigated. The samples were synthesized by a solid state reaction (sample A), by coprecipitation of the hydroxocarbonates (sample B), and by the sol–gel technique (sample C). According to data from X-ray diffraction (XRD) and the temperature dependence of the specific resistance a single-phase superconductor is formed in the sol–gel method and has the highest critical temperature for transition to the superconducting state (Tc = 95 K), whereas samples A and B contain impurity phases and have lower critical temperatures for transition (92 and 87 K, respectively).