Magnetic Phase Transitions in Systems with Competing Interactions

D. P. Landau

《Chinese Journal of Physics》 15卷2期 (1977/07) Pp. 116-123

並列摘要

Phase transitions in magnetic systems are studied using a Monte Carlo computer simulation method. The fundamentals of the technique are described and the strengths and limitations of this approach are discussed. Comparisons are made between the Monte Carlo data and exact results for the Ising square lattice. The properties of several different types of anisotropic systems are determined with particular care taken near the critical temperature Tc Competing interactions between neighboring sites has the effect of shifting Tc and may, in some cases, even change the nature of the ordered magnetic state. Critical field boundaries are traced out for several antiferromagnets and we show how competing interactions may give rise to tricritical points. We also present data on systems with impurities and examine the effects of free surfaces on the phase transition. Lastly we show how the transformation from the 2-dim Ising model to its lattice-gas model equivalent allows us to study adsorbed gas monolayers.