Two-dimensional quasicrystals of decagonal order in one-component monolayer films.

By using Monte Carlo simulations we demonstrate that atomic monolayers formed on a crystalline surface may exhibit quasicrystalline decagonal order. It is shown that the stability of two-dimensional quasicrystals (QCs) is determined by the misfit between the adsorbate and the surface lattice and by the corrugation of the surface potential. QCs may be stable at the ground state or develop from the compressed commensurate c(2 x 2) structure, via the first-order phase transition at finite temperatures. The decagonally ordered phase melts into a partially ordered liquidlike phase, which then disorders via a continuous Ising-like transition.