Statistical thermodynamics of aligned rigid rods with attractive lateral interactions: Theory and Monte Carlo simulations

DOS SANTOS, G.J.; LINARES, D.H.; RAMIREZ-PASTOR, A.J.

PHYSICA A - STATISTICAL AND THEORETICAL PHYSICS

ELSEVIER SCIENCE BV

Año: 2018 vol. 495 p. 81 - 93

0378-4371

The phase behaviour of aligned rigid rods of length k (k-mers) adsorbed on two-dimensionalsquare lattices has been studied by Monte Carlo (MC) simulations and histogram reweightingtechnique. The k-mers, containing k identical units (each one occupying a lattice site)were deposited along one of the directions of the lattice. In addition, attractive lateralinteractions were considered. The methodology was applied, particularly, to the study ofthe critical point of the condensation transition occurring in the system. The process wasmonitored by following the fourth order Binder cumulant as a function of temperature fordifferent lattice sizes. The results, obtained for k ranging from 2 to 7, show that: (i) thetransition coverage exhibits a decreasing behaviour when it is plotted as a function of thek-mer size and (ii) the transition temperature, Tc , exhibits a power law dependence on k,Tc ∼ k0,4, shifting to higher values as k increases. Comparisons with an analytical modelbased on a generalization of the Bragg?Williams approximation (BWA) were performedin order to support the simulation technique. A significant qualitative agreement wasobtained between BWA and MC results