Directed reaction process producing single-phase superconducting compound YBa2Cu3O6.5+σ

摘要: Abstract A directed reaction process (DRP) based on physico-chemical principles has been used for producing single-phase 90 K “zero- resistance” superconducting compound YBa 2 Cu 3 O 6.5+σ . The reliability of the DRP well proved by stability and reproducibility results in resistance a.c. magnetic susceptibility measurements samples taken randomly from five consecutive batches products. products were identified X-ray diffraction as polycrystalline material orthorhombic structure with lattice parameters a = 3.89A, b 3.82A c 11.65A. nonstoichiometric fraction, value, was determined to be + 0.27.