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abstract: 'A solid-on-solid model is proposed to describe faceting of bcc(111) metal surface induced by a metal overlayer. It is shown that the first order phase transition occurs between faceted {211} or {110} and disordered phases. The ordered phases consist of large 3-sided pyramids with {211} facets or {110} facets. It is shown that the high-temperature disordered phase has not planar bcc(111) structure but faceted disordered structure. Hysteresis effects were observed when the system was warmed above the transition temperature and then cooled down. Temperature dependence of LEED patterns for faceted and disordered phase are calculated in kinematic approximation.'
author:
- 'Czes[ł]{}aw Oleksy'
date: 'March 4, 2003'
title: SOS model of overlayer induced faceting
---

Introduction
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Recent experiments [@mad99a; @mad99b; @mad96; @mad94; @mad97; @mad95; @song95] have demonstrated that surfaces such as W(111) and Mo(111) covered by a single physical monolayer of certain metal, e.g., Pd, Pt, undergo massive reconstruction from planar morphology to microscopically faceted surface after annealing to $T>700 K$. The reconstructed surface consists of 3-sided pyramids with mainly $\{211\}$ facets, and pyramid dimensions range from $\sim 1$ to 100 nm. It has been shown that facets are composed of substrate atoms, and the monolayer of adsorbate 