LATTICE GAS SIMULATION OF OXYGEN ORDERING IN YBa2Cu3O6+x SHOWING DYNAMICAL SCALING

Abstract

A 2-dimensional anisotropic lattice model for the oxygen ordering in the high Tc superconductor of the YBa 2 Cu 3 O 7+x type is shown to exhibit an ordering dynamics that obey algebraic growth laws which depend on whether it is an Ortho-I or Ortho-II phase. It is possible to relate this dynamical scaling behavior to a similar scaling in the experimentally observed temporal variation of the superconductivity transition temperature and hence suggesting a specific coupling between the coherence of oxygen order in the basal Cu-O planes and the superconducting state. Furthermore it is possible to explain the variation in the transition temperature with the oxygen density x by a phase mixing model of Ortho-II/Ortho-I domains and an assumption about the charge transfer between the basal and superconducting plane.