Complex magnetic phase in submonolayer Fe stripes on Pt(997)

J. Honolka1, T.Y. Lee1, K. Kuhnke1, D. Repetto1, V. Sessi1, P. Wahl1, A. Buchsbaum2, P. Varga2, S. Gardonio3, C. Carbone3, S.R. Krishnakumar4, P. Gambardella5, M. Komelj6, R. Singer7, M. Fähnle7, K. Fauth7, G. Schütz7, A. Enders1, K. Kern1,8

1 Max-Planck-Institut für Festkörperforschung, 70569 Stuttgart, Germany
2 Institut für Allgemeine Physik Technische Universität Wien, 1040 Wien, Austria
3 Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Area Science Park, 34012 Trieste, Italy
4 International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34100 Trieste, Italy
5 Institució Catalana de Recerca i Estudis Avançats (ICREA) and Centre d'Investigacions en Nanociència i Nanotecnologia (CSIC-ICN), UAB Campus, 08193 Bellaterra, Spain
6 Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
7 Max-Planck-Institut für Metallforschung, Heisenbergstrasse 13, 70569 Stuttgart, Germany
8 Institut de Physique des Nanostructures, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

Phys. Rev. B 79 (2009) 104430

Correlations between magnetism and morphology of iron nanostructures of monatomic height on Pt(997) substrates are studied using x-ray magnetic circular dichroism as well as scanning tunneling microscopy and helium scattering. A drastic collapse of the average magnetization by more than a factor of 4 is observed when increasing the iron coverage from 0.1 to 0.2 ML. This effect goes along with a softening of the magnetic anisotropy energy and a gradual reorientation of the magnetic easy axis from in plane to out of plane. The experimental findings together with electronic density-functional calculations suggest the formation of a complex magnetic phase in corrugated rim regions of Fe islands, leading to both ferromagnetic and antiferromagnetic exchange couplings of Fe moments depending on their various local bonding configurations.

Corresponding author: J. Honolka. Reprints also available from M. Schmid (schmid< encoded email address >).

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