Sequence of incommensurate phases in a model of surface reconstruction and roughening

A solid-on-solid–type model is proposed in order to provide a unified description of both the surface reconstruction and roughening phase transitions. A low-temperature domain-wall analysis reveals the presence of several incommensurate phases, separated by continuous phase transitions, for all temperatures T>0. True commensurate order develops only at T=0, a pseudo commensurate-incommensirate transition at ${\mathit{T}}_{\mathit{c}}^{\mathrm{*}}$>0, and a high-temperature roughening transition terminates the sequence of incommensurate phases. The resulting phase diagram may apply to the description of the pure and alloyed noble-metal [110] solid-vapor interface structure.