Monte Carlo Simulation of Temperature Programmed Desorption Spectra:  A Guide through the Forest for Monomolecular Adsorption on a Square Lattice

Abstract

A comparative study of thermal desorption spectra obtained through Monte Carlo simulation for monomers, symmetric dimers, and asymmetric dimers, on heterogeneous surfaces presenting different topographies of two kind of sites, is presented in such a way as to serve as a guide for the interpretation of experimental data.

Monte Carlo Simulations for Tomlinson Sliding Models for Non-Sinusoidal Periodic Potentials

“…The lateral frictional force was calculated using Monte Carlo strategies as described elsewhere [11,17], while constraining the experimental lattice constant for mica to be a = 0.52 nm, the lateral cantilever force constant k L to be the measured value of 1.2 N/m, and the frequency factor m 0 also to be the experimentally determined value of 19.5 kHz [7]. The temperature was fixed at the experimental value of 298 K. Only the height of the Tomlinson/Prandtl potential E 0 was allowed to vary for each value of normal load.…”

Adsorption–desorption kinetics of the monomer–dimer mixture

“…However, the number of equations is too large and the method becomes unpractical. Monte Carlo simulations seem to be the adequate a b c d The desorption process is simulated by a kinetic Monte Carlo algorithm introduced by Sales et al [12]. The particles that are in equilibrium with the gas phase are simulated using a Metropolis dynamics.…”

“…The theory of the adsorption-desorption kinetics on homogeneous surfaces is by now well understood [1][2][3][4][5][6][7][8][9][10][11][12]. The simple model formulated by Langmuir describes the kinetics of adsorption on homogeneous surfaces, based on the law of mass action.…”

“…Graphical representation of the adsorbate-adsorbate interactions, i.e., monomer-monomer: 11 , monomer-dimer:12 and dimer-dimer:22 .…”

Sequential desorption of dimers from square lattices: A novel mechanism for phase transitions

“…However, the phenomenon occurring at the molecular scale is hard to infer straightforwardly from the TPD spectra. For the case of simple molecules chemisorbed on single-crystal surfaces where there is a regular structure of the surface and bulk atoms, along with the strongly localized nature of chemisorption, it is possible to model the adlayer in terms of the lattice-gas approach [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The strong molecule-molecule interaction makes the equilibrium and dynamics of adlayers one of the most challenging problems to be addressed by classical statistical mechanics.…”