Monte Carlo study of transient states of order in ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{\mathrm{z}}$

Monte Carlo simulations of oxygen ordering in the ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathrm{z}}$ system have been performed using a two-dimensional anisotropic Ising model. In agreement with experimental findings, transient phases are obtained at low temperatures. Observed structures are investigated, and the kinetics of their domain formation is described. The convergence of the system is seen to be exceptionally slow, and the rate of domain evolution is found to increase with decreasing oxygen content. The implications of these findings on the development of a complete theoretical ordering model for this system are discussed.