Magnetisation dynamics of Fe nanoclusters exchange-coupled to magnetic substrates

• Published in: Physica status solidi. A, Applied research Vol. 201; no. 15; pp. 3285 - 3292
• Main Authors: Binns, C., Sirotti, F., Cruguel, H., Baker, S. H., Prieto, P., Bellier, J. D., Thornton, S. C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-12-2004; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: 75.30.Et; 75.40.Gb; 75.50.Tt; 75.70.-i; 79.60.Dp; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Physics; Magnetization reversal; Photoelectron spectra; Magnetic dichroism; Magnetization; Iron; Amorphous state; Coverage rate; Core levels; Time resolved spectra; Switching; Interfaces; Solid clusters; Angular distribution; Molecular field approximation; Nanostructured materials; Exchange interactions; Synchrotron radiation
• ISSN: 0031-8965; 1521-396X
• DOI: 10.1002/pssa.200405439

Synchrotron radiation was used to study exposed Fe nanoclusters with controlled sizes in the size range 140–270 atoms (1.5–1.8 nm) deposited in situ from a gas aggregation source on to magnetic vitrovac amorphous ribbons. Magnetic linear dichroism in the angular distribution (MLDAD) of the Fe 3p core level photoemission was used to show that the clusters are exchange‐coupled to the substrate with an interface molecular field of about 20 T. The switching dynamics was studied on the nanosecond timescale by time‐resolved spin‐polarised photoemission. At low coverages, below the percolation threshold, when the film consists of separated islands the switching dynamics of the cluster islands is identical to the clean substrate. At around the percolation threshold, however, the data indicates that the magnetic reversal propagates faster in the cluster film than in the substrate. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)