Crystallographic description of phases in the Y-Ba-Cu-O superconductor
Abstract
Single-crystal x-ray techniques were used to determine two structures that comprise the Y-Ba-Cu-O superconductor. A green phase has the orthorhombic Y2BaCuO5 structure. An opaque phase (YBa2Cu3O6+x, 0<=x<=1.0) is tetragonal (a=3.859 Å, c=11.71 Å space group P4¯m2Z=1). The structure is related to a 1:1:3 ABO3 perovskite: Ba and Y order in A sites and Cu is in B sites. Systematic oxygen vacancies between adjacent copper atoms lead to a fivefold-coordinate Cu in proximity to Y and a twofold-coordinate Cu in the vicinity of the Ba site.
- Publication:
-
Physical Review B
- Pub Date:
- May 1987
- DOI:
- 10.1103/PhysRevB.35.7238
- Bibcode:
- 1987PhRvB..35.7238H
- Keywords:
-
- Barium Oxides;
- Copper Oxides;
- Crystal Structure;
- Mixed Oxides;
- Superconductors;
- Yttrium Oxides;
- Perovskites;
- Single Crystals;
- Solid-State Physics;
- 74.70.Ya;
- 61.60.+m;
- 61.70.Ey;
- 74.90.+n;
- Other topics in superconductivity