The impact of an applied electric field on exchange coupling parameters has been investigated based on first-principles electronic structure calculations by means of the Korringa-Kohn-Rostoker Green function method. The calculations have been performed for a Fe film, free-standing and deposited on two different substrates, having 1 monolayer (ML) thickness to minimize the effect of screening of the electric field typical for metallic systems. By comparing the results for the free-standing Fe ML with those for Fe on the various substrates, we could analyze the origin of the field-induced change of the exchange interactions. Compared to the free-standing Fe ML, in particular rather pronounced changes have been found for the Fe/Pt(111) system due to the localized electronic states at the Fe/Pt interface, which are strongly affected by the electric field and which play an important role for the Fe-Fe exchange interactions.

• Received 4 August 2021
• Revised 8 November 2021
• Accepted 15 November 2021

DOI:https://doi.org/10.1103/PhysRevB.104.174443