Phase diagram and ground state of a decorated antiferromagnetic Ising model on a triangular lattice with nearest and next nearest neighbor interactions

The static critical behavior of the two-dimensional decorated Ising model on a triangular lattice is studied using computational physics methods. The exchange interaction between the nearest nodal neighbors and between the next nearest nodal neighbors was antiferromagnetic. The exchange interaction between nodal and decorated spins varied over a wide range from antiferromagnetic to ferromagnetic. The ground state of the model is determined, critical temperatures are calculated, and the phase diagram is constructed for the entire range of exchange interactions between nodal and decorated spins. Our results showed that decoration can lead to frustration effects, the appearance of new phases, and change the type of phase transition depending on the value and sign of the decorated exchange interaction.