Repositorio
Institucional

Ramirez-Pastor, Antonio José

Pasinetti, P. M.

Ramirez-Pastor, A. J.

Vogel, E. E.

Entropy-driven phases at high coverage adsorption of straight rigid rods on three-dimensional cubic lattices

AMER PHYSICAL SOC

PHYSICAL REVIEW E

en

Combining Monte Carlo simulations and thermodynamic integration method, we study the configurational entropy per site of straight rigid rods of length k (k-mers) adsorbed on three-dimensional (3D) simple cubic lattices. The process is monitored by following the dependence of the lattice coverage. on the chemical potential mu (adsorption isotherm). Then, we perform the integration of mu(theta) over theta to calculate the configurational entropy per site of the adsorbed phase s(k, theta) as a function of the coverage. Based on the behavior of the function s(k, theta), different phase diagrams are obtained according to the k values: k <= 4, disordered phase, k = 5, 6, disordered and layered-disordered phases, and k >= 7, disordered, nematic and layered-disordered phases. In the limit of theta -> 1 (full coverage), the configurational entropy per site is determined for values of k ranging between 2 and 8. For k >= 6, MC data coincide (within the statistical uncertainty) with recent analytical predictions [D. Dhar and R. Rajesh, Phys. Rev. E 103, 042130 (2021)] for very large rods. This finding represents the first numerical validation of the expression obtained by Dhar and Rajesh for d-dimensional lattices with d > 2. In addition, for k >= 5, the values of s(k, theta -> 1) for simple cubic lattices are coincident with those values reported in [P. M. Pasinetti et al., Phys. Rev. E 104, 054136 (2021)] for two-dimensional (2D) square lattices. This is consistent with the picture that at high densities and k >= 5, the layered-disordered phase is formed on the lattice. Under these conditions, the system breaks to 2D layers, and the adsorbed phase becomes essentially 2D. The 2D behavior of the fully covered lattice reinforces the conjecture that the large-k behavior of entropy per site is superuniversal, and holds on d-dimensional hypercubical lattices for all d >= 2.

2023

artículo original

10.1103/PhysRevE.107.064126

PDF

Monte Carlo methods

Lattice models in statistical physics

Classical statistical mechanics

Interface & surface thermodynamics

Phase transitions

Física

métodos de Montecarlo

Modelos reticulares en física estadística

Mecánica estadística clásica

Termodinámica de interfaces y superficies

Transiciones de fase

artículo original

versión publicada

metadata

metadata

WOS:001055201000005

2470-0045

verde

Física

CONICET PIP 112-201101-00615

UNSL 03- 1920

ANID AFB220001

ANID-FONDECYT 1230055

ANID FONDECYT 1230055