Ultra-Thin Films on Complex Metallic Alloy Surfaces: A Perspective

Abstract

Complex metallic alloys (CMAs) may be defined as those intermetallic compounds having large (>≈nm) unit cell dimensions. This includes quasicrystals as a special case, the unit cell being infinite. The discovery of quasicrystals motivated the study of CMAs, and the surface science community became active in the field once stable samples of sufficient size were produced. While the initial surface science activity centred on clean surface preparation, increasingly the formation of thin films, both metallic and molecular grew in importance. In this chapter we give a brief introduction to this topic, and then focus on several current areas of interest. These include the growth and characterisation of ultrathin metallic films of diverse architectures, the formation through deposition of novel molecular overlayers and thin films, complex intermetallics as surface alloys, and the potential use of intermetallic surfaces for catalytic reactions.

From high temperature phase formation to transition metal substitution in the Fe/Al9Co2(001) system

“…These works have highlighted complex energy landscapes, characteristics exploited to propagate complexity in elemental and molecular thin films [10,11,12]. For specific systems and under particular growth conditions, CMA have also been formed voluntarily or fortuitously as surface alloys [13]. We can refer for instance to the formation of Al 4 Cu 9 while aiming to form single element thin films on quasicrystalline and approximant surfaces [14,15,16].…”