Structure of High-Tc Superconductor YBa2Cu3O6.6 at Low Temperatures

Abstract

A single-phase YBa₂Cu₃O_6.6 shows a sharp superconductive transition at 94 K. The crystal structure of this compound has been determined by the Rietveld profile analysis of neutron powder diffraction data measured at 10 K and 120 K. The space group Pmmm is confirmed, and the positions and occupations of oxygen atoms are established. No phase transitions or other structural anomalies were observed in relation to the superconductive transition.