"Devil's staircases" in bulk-immiscible ultrathin alloy films.
Ground-state phase diagrams of ultrathin epitaxial alloy films are studied within the framework of a discrete lattice-model Hamiltonian incorporating competing elastic and chemical interactions. For bulk-immiscible alloy systems an infinite number of commensurate, long-period stripe-superstructure ground states are obtained as a function of chemical potential. The average periodicity of these stripe superstructures is found to be a nonmonotonic function of alloy composition, in contrast to the predictions of continuum theories for two-dimensional systems with competing interactions.
Krack
B D
BD
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
Ozoliņs
V
V
Asta
M
M
Daruka
I
I