Magnetic phases of ultrathin Fe grown on Cu(100) as epitaxial wedges

Abstract

Magnetic wedges of Fe on Cu(100) are explored magneto-optically. In the region of 6–11 monolayers (ML) of fcc Fe grown at room temperature, in addition to a surface ferromagnetic layer with a Curie temperature ∼250 K, the Fe bulk is antiferromagnetic with a Néel temperature of ∼200 K. This fcc phase is stable only above a growth temperature of order ∼200 K, below which the ferromagnetic spin-reorientation transition occurs at ∼6 ML. The phase boundaries are delineated by cusps in the coercivity along the wedge.