S = 1 Ising model on a triangular lattice

Abstract We study the S =1 Ising model on a triangular lattice with antiferromagnetic nearest-neighbour coupling and second and third neighbour interactions. We also consider the effect of anisotropy. At low temperature several phases where magnetic and nonmagnetic sites coexist are obtained because of magnetic frustration. The evolution with temperature and field is particularly interesting due to the competition of different structures which are very close in energy.