States of partial order in YBa2Cu3Oz

Abstract

Monte Carlo simulation has been performed on a previously proposed model of oxygen ordering in ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathrm{z}}$: A two-dimensional Ising model with isotropic first-neighbor and anisotropic second-neighbor effective pair interactions in the ‘‘chain plane.’’ At low temperatures, states of partial order are observed in agreement with experimental findings. Such states of quasi-one-dimensional order are a consequence of the asymmetric nature of the interactions.