title: Frozen low-spin interface in ultrathin Fe films on Cu(111).
abstract: In ultrathin film systems, it is a major challenge to understand how a thickness-driven phase transition proceeds along the cross-sectional direction of the films. We use ultrathin Fe films on Cu(111) as a prototype system to demonstrate how to obtain such information using an in situ scanning tunneling microscope and the surface magneto-optical Kerr effect. The magnetization depth profile of a thickness-driven low-spin to high-spin magnetic phase transition is deduced from the experimental data, which leads us to conclude that a low-spin Fe layer at the Fe/Cu interface stays live upon the phase transition. The magnetically live low-spin phase is believed to be induced by a frozen fcc Fe layer that survives a thickness-driven fcc-->bcc structural transition.
authors.affiliation: Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Torija
authors.forename: Z
authors.initials: Z
authors.lastname: Gai
authors.forename: N
authors.initials: N
authors.lastname: Myoung
authors.forename: E W
authors.initials: EW
authors.lastname: Plummer
authors.forename: J
authors.initials: J
authors.lastname: Shen