Topological Aspects of the (1 × 1) ⇌ “Hexagonal” Phase Transition on Pt(100)

Abstract

Abstract We have investigated the (1 × 1) ⇌ “hexagonal” phase transition on Pt(100) by Scanning Tunneling Microscopy with special emphasis on the density change of the topmost Pt layer correlated to this process. It was found that in both directions extra atoms are accommodated in monolayered islands on top of the flat substrate. The size of the islands mainly depends on the transition temperature, from 25 Å at 375 K to 100 Å at 550 K, which is explained by a stability increase of these islands with increasing size, in agreement with thermodynamic arguments over interface tension.