Fluctuations, commensurability, and structures found in Monte Carlo simulations of finite one-dimensional chains on a periodic substrate

摘要

Finite one-dimensional chains adsorbed on a periodic potential were simulated using a hybrid isobaric ensemble. Our simulations are unique because we observe structures forbidden in macroscopic systems. Density fluctuations dominate the system and produce a mixture of coexisting thermodynamic structures. Stable structures were rare. We applied a lattice gas approximation to the observed fragmentations in the chains with success. Our goal was to test these systems for experimentally measurable changes in enthalpy. Chains fragment into clusters having nearly the same size, which contrasts with the size distributions found in three-dimensional vapors.