Thermodynamics of oxygen ordering in YBa2Cu3Oz
Abstract
The ordering in the Cu-O basal plane of YBa2Cu3Oz is investigated as a function of oxygen content and temperature. A phase diagram is calculated by application of the cluster variation method to an asymmetric two-dimensional Ising model. The interaction parameters selected guarantee the stability of the experimentally observed double-cell structure around z=6.5. The transition temperatures at various oxygen partial pressures are in good agreement with experiment. The pair probabilities along the Cu-O chains show a plateau with varying oxygen concentration, not unlike the dependence of Tc on oxygen content.
- Publication:
-
Physical Review Letters
- Pub Date:
- March 1988
- DOI:
- 10.1103/PhysRevLett.60.1065
- Bibcode:
- 1988PhRvL..60.1065W
- Keywords:
-
- Mixed Oxides;
- Order-Disorder Transformations;
- Oxygen;
- Phase Diagrams;
- Thermodynamic Properties;
- Yttrium Oxides;
- Barium Oxides;
- Copper Oxides;
- Ground State;
- Transition Temperature;
- Two Dimensional Models;
- Solid-State Physics;
- 74.70.Vy;
- 61.50.Ks;
- 64.60.Cn;
- 81.30.Hd;
- Crystallographic aspects of phase transformations;
- pressure effects;
- Order-disorder transformations;
- statistical mechanics of model systems;
- Constant-composition solid-solid phase transformations: polymorphic massive and order-disorder