Phase Diagram of Adsorbate-Induced Row-Type-Alignments

TL;DR

This paper models the phase diagram of adsorbate-induced row alignments on FCC(110) surfaces using the BEG model, revealing complex phases due to competing interactions.

Contribution

It introduces a BEG model with adatom and dipole interactions to analyze surface reconstructions, providing new insights into phase behavior.

Findings

Incommensurate phases appear at high temperatures with competing interactions.

Mean-field approximation used to calculate phase diagrams.

Competition between NN and NNN interactions leads to diverse phases.

Abstract

The phase diagram of adsorbate-induced row-type-alignments, such as missing-row reconstructions induced by adsorbate-atoms on the FCC(110) surface, is calculated by the Blume-Emmery-Griffiths (BEG) model. In the model, we introduce adatom-adatom and dipole-dipole interactions between nearest-neighbor (NN) and next-nearest-neighbor (NNN) rows. The calculation of the temperature versus adatom chemical potential phase diagram is performed using mean-field approximation. It is indicated that when NN and NNN interactions are competitive, there appear either dipole or coverage modulated (incommensurate) phases at high temperatures for wide regime of the interactions.