Structure of the single-phase high-temperature superconductor YBa2Cu3O7−δ

Abstract

We have determined the crystal structure of the single‐phase stoichiometric high‐temperature superconductor in the Y‐Ba‐Cu‐O system using high‐resolution neutron powder diffraction. This compound has an orthorhombic structure with space group Pmmm and lattice constants a=3.8231 Å, b=3.8864 Å, and c=11.6807 Å. The structure consists of ‘‘dimpled’’ CuO₂ layers in the a‐b planes loosely bonded by one‐dimensional fencelike square‐planar CuO₃ chains in the b‐c planes.