Sv. Stroganova et al., The effect of vibrational degrees of freedom on the phase transition in a 2D Ising model, PHYSICA A, 274(1-2), 1999, pp. 367-373
The aim of this work is to show how important small atomic vibrations can b
e for the equilibrium state of a binary alloy or a lattice gas of adatoms o
n a surface. Using the Monte-Carlo procedure and performing direct lattice
dynamics calculations, the total (configurational plus vibrational) free en
ergy of the system is obtained. The calculations show that, if the differen
ce in the bond stiffness between like and unlike atoms is large, it is poss
ible to introduce a renormalised interaction constant and to treat the syst
em as Ising-like. For this case, the effects of lattice dynamics parameters
on the order-disorder transition temperature are discussed. (C) 1999 Elsev
ier Science B.V. All rights reserved.