Phase diagram and superconductivity in the Y-Ba-Cu-O system

Abstract

We have determined the phase diagram of the Y-Ba-Cu-O system through structural, superconducting critical temperature and critical current density characterization. Our results show that a single-phase compound with a stoichiometry YBa2Cu3Oy is responsible for the high-temperature superconductivity (92.5 K) in this system.

Past and present crystallographic work at the NBS/NIST reactor

“…Superconductivity with T c ≈94 K was discovered in a sample which was a mixture of phases [51] and, again, the superconducting compound was identified later in several laboratories as YBa 2 Cu 3 O x , with x ≈7.0 [52–54]. Profile analysis based on neutron powder data quickly gave an accurate description of the structure which is shown in Fig.…”

The Plausible Motion's Confinement of Electrons by the Structure in YBa2Cu3O7‐x

“…5 Soon after this discovery, the single-phase compound responsible for the high T C superconductivity as YBa 2 Cu 3 O 7-x was identified by several groups. [6][7][8] From the x-ray powder diffraction data, Cava et al 6 determined an orthorhombic structure that could be described as an oxygen deficient perovskite with tripling of the c-axis caused by the ordering of the Ba and Y atoms. The neutron diffraction experiments confirmed the space group P mmm and the main structure features of YBa 2 Cu 3 O x for 6.8 £ x £ 7.0.…”

Influence of the heat treatment on the structure of SmBa2Cu3O7−x

“…Most of the rare earth elements form with barium and copper a perovskite phase of the YBa2Cu3OT_x type, appearing in two structural modifications, tetragonal and erthorhombic [1][2][3][4][5][6][7][8]. The tetragonal phase is not superconducting, whereas the orthorhombic phase shows superconducting properties, with a transition temperature into the superconducting state depending on the oxygen content [5,9].…”