Critical temperature studies of the anisotropic bilayer and multilayer Heisenberg ferromagnets in Pair Approximation

► Pair Approximation method developed for bilayer/multilayer magnetic systems. ► Focus on the critical temperature of S=1/2 anisotropic ferromagnetic Heisenberg model. ► Quantum effects from non-Ising couplings included in complete thermodynamic description. ► Compensation effect for Curie temperature found in bilayer with unequal intraplanar interactions. ► Saturation of Curie temperature for strong interplanar couplings in some systems found.