Surfactant-assisted epitaxial growth and magnetism of Fe films on Cu(111)

Abstract

The magnetic properties of thin epitaxial layers of Fe grown on Cu(111) depend sensitivelyon the films’ structure and morphology. A combination of experiments and numericalsimulations reveals that the use of a surfactant monolayer (ML) of Pb during molecularbeam epitaxy (MBE) growth at room temperature reduces the amount of interdiffusion atthe Cu–Fe interface, retards the fcc-to-bcc transformation by about 2 ML and substantiallyincreases the films’ coercivity. The origin of all these alterations to the magnetic behaviorcan be traced back to the structural modifications provoked by the surfactantduring the early growth stages. These results open the way for the controlledfabrication of custom-designed materials with specific magnetic characteristics.