Ferromagnetic phase breakdown of a quenched bond-mixed Ising model

Within the framework of an effective field theory beyond Mean Field Approximation, we discuss the ferromagnetic phase stability limit in the temperature-concentration space of a quenched bond-mixed spin-$\text{1}\text{2}$ Ising model in square lattice for both competing and noncompeting interactions J₁ and J₂. Quite reasonable results are obtained in both situations. In particular for the case of competing interactions, numerical estimates of the vanishing temperature critical bond concentrations are predicted for particular values of the ratio $\text{J}{}_1\text{J}{}_2$.