Metal Thin Film Growth on Metals: Surfactant Effects

Abstract

Surfactant-assisted growth is a widely used technique for tailoring the properties of ultrathin epitaxial metallic films. The main effect of surfactants is switching the growth mode from islanding to layer by layer, allowing the development of smooth surfaces and interfaces. Besides to be excellent assistants of epitaxial growth, surfactants often modify also the magnetic properties of the surfaces, enhancing the magnetic moments of the outmost atoms or changing the magnetic anisotropy of the system. Finally, the presence of surfactant species can support the development of epitaxial metastable phases, increasing the stability range and/or changing the mechanism of transition toward the bulk phase. By considering examples from the recent literature, the basic mechanisms by which a single layer of foreign atoms adsorbed on the surface modifies the morphological, structural, and magnetic properties of ultrathin metallic films will be discussed.