2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/140365An explicit expression for the partition function of two-dimensional nearest neighbour Ising models in the presence of a magnetic field is derived by a systematic enumeration of all the spin configurations pertaining to a square lattice of sixteen sites. The critical temperature is shown to be in excellent agreement with the reported values while the corresponding dimensionless magnetic field is obtained as 0.004.14 pages, 3 FiguresStatistical Mechanicstext