title: Tailoring the nature of magnetic coupling of Fe-porphyrin molecules to ferromagnetic substrates.
abstract: We demonstrate that an antiferromagnetic coupling between paramagnetic Fe-porphyrin molecules and ultrathin Co and Ni magnetic films on Cu(100) substrates can be established by an intermediate layer of atomic oxygen. The coupling energies have been determined from the temperature dependence of x-ray magnetic circular dichroism measurements. By density functional theory+U calculations the coupling mechanism is shown to be superexchange between the Fe center of the molecules and Co surface-atoms, mediated by oxygen.
authors.affiliation: Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany. bernien@physik.fu-berlin.de
authors.forename: M
authors.initials: M
authors.lastname: Bernien
authors.forename: J
authors.initials: J
authors.lastname: Miguel
authors.forename: C
authors.initials: C
authors.lastname: Weis
authors.forename: Md E
authors.initials: ME
authors.lastname: Ali
authors.forename: J
authors.initials: J
authors.lastname: Kurde
authors.forename: B
authors.initials: B
authors.lastname: Krumme
authors.forename: P M
authors.initials: PM
authors.lastname: Panchmatia
authors.forename: B
authors.initials: B
authors.lastname: Sanyal
authors.forename: M
authors.initials: M
authors.lastname: Piantek
authors.forename: P
authors.initials: P
authors.lastname: Srivastava
authors.forename: K
authors.initials: K
authors.lastname: Baberschke
authors.forename: P M
authors.initials: PM
authors.lastname: Oppeneer
authors.forename: O
authors.initials: O
authors.lastname: Eriksson
authors.forename: W
authors.initials: W
authors.lastname: Kuch
authors.forename: H
authors.initials: H
authors.lastname: Wende