EFFECT OF INTERLAYER COUPLING ON NEEL, TEMPERATURE IN COPPER-OXIDE BASED ANTIFERROMAGNETS

The role of interlayer coupling (J(perpendicular to) ) on the Neel temperature of (1-2-3) compounds is studied by taking the three-dimensional anisotropic Heisenberg antiferromagnetic model. The two-sublattice model of the antiferromagnet is considered. The double-time Green function technique is employed and the higher-order Green functions are decoupled using the Callen decoupling approximation. The Neel temperature (T-N) for YBa2Cu3O6+x (1-2-3) compounds as a function of doping concentrations (x) is estimated. The intraplanar coupling strength (J(parallel to)) is treated as a constant throughout the numerical calculations. The theoretical results are compared with that of the random phase approximation (RPA) and existing experimental results.