Physical review. B, Solid state
Monte Carlo studies on small Ising systems
H. C. Bolton, David W. R. Gruen
Abstract
Results are presented for the critical temperatures ${T}_{n}$ of small $n\ifmmode\times\else\texttimes\fi{}n$ Ising clusters using one of the extended mean-field boundary conditions recently introduced by Bolton and Johnson. The spin flips were simulated numerically. The values of ${T}_{n}$ were obtained by extrapolating to zero the long-range order below ${T}_{n}$. The extrapolation to the infinite limit $n=\ensuremath{\infty}$ was performed using an expansion in powers of $\frac{1}{n}$ and the final result agrees to 2% with the Onsager value.