A new method for the antiferromagnetic Ising modelʹs properties at any temperature and any magnetic field on the infinite square lattice

Since the introduction of the Ising model on the square lattice, many hundreds of articles have dealt with several properties of the ferromagnetic Ising model, but very few articles had included the antiferromagnetic Ising model. We have known that the Ising antiferromagnetism on a bipartite lattice is not zero in a considerable area of the magnetic field, H, and temperature, T. Now we present the dimensionless specific heat, C, and susceptibility, χ, per vertex using a new method to obtain the data in about 10,000 points in the interesting (T,H) area. Our last four figures show the contours and the smooth hills and valleys of C and of χ.