Surface spin polarization of Fe nanoclusters

Andrew Pratt, Charles Woffinden, Roland Kroger, Steve P. Tear, Chris Binns

Research output: Contribution to journalArticlepeer-review


The spin polarization at the surface of Fe nanoclusters has been probed using a spin-polarized metastable helium beam. The clusters, produced in a gas aggregation source, display a lognormal size distribution with a peak centered at similar to 11 nm. Varying coverages of both spheroid-and cuboid-shaped particles were concomitantly deposited onto clean Si(111) substrates for investigation with the extremely surface sensitive technique of metastable de-excitation spectroscopy (MDS). A nominal cluster coverage of 8 angstrom yielded a maximum asymmetry of similar to 10% in the ejected electron yield for He spins aligned parallel and anti-parallel to the magnetization direction of the clusters. When compared to values obtained from epitaxial Fe films on various substrates, the measured asymmetry suggests an enhancement in the surface spin polarization, as theoretically proposed. The atomic structure of the clusters and their topography on the Si(111) substrates were studied with transmission and scanning electron microscopy.

Original languageEnglish
Article number5467480
Pages (from-to)1660-1662
Number of pages3
JournalIEEE Transactions on Magnetics
Issue number6
Publication statusPublished - Jun 2010

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  • Metastable de-excitation spectroscopy
  • nanoclusters
  • spin polarization
  • surface magnetism

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