title: Hysteretic behaviour in a vacuum deposited submonolayer of single ion magnets.
abstract: With element-specific X-ray absorption spectroscopy and X-ray magnetic circular dichroism we have investigated submonolayer coverages of TbPc2 and DyPc2 molecules sublimated on highly ordered pyrolytic graphite. We have studied the field dependence of the magnetization of the central lanthanide ion at very low temperatures. Even in zero applied magnetic field we still observe a remanence in the magnetization. Since there are neither intermolecular coupling nor magnetic interactions with the substrate, this remanent behaviour results just from single-ion anisotropy. On the very inert surface of graphite at temperatures between 0.5 K and 2 K the spin relaxation is slow enough to observe a memory effect in the timescale of the experimental measurements.
authors.affiliation: Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Lotharstraße 1, D-47048 Duisburg, Germany. david.klar@uni-due.de.
authors.forename: David
authors.initials: D
authors.lastname: Klar
authors.forename: Andrea
authors.initials: A
authors.lastname: Candini
authors.forename: Loïc
authors.initials: L
authors.lastname: Joly
authors.forename: Svetlana
authors.initials: S
authors.lastname: Klyatskaya
authors.forename: Bernhard
authors.initials: B
authors.lastname: Krumme
authors.forename: Philippe
authors.initials: P
authors.lastname: Ohresser
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Kappler
authors.forename: Mario
authors.initials: M
authors.lastname: Ruben
authors.forename: Heiko
authors.initials: H
authors.lastname: Wende