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.
|Copyright, Publisher and Additional Information:||© 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.|
|Keywords:||Metastable de-excitation spectroscopy,nanoclusters,spin polarization,surface magnetism,FILMS,MAGNETISM,CLUSTERS,Electrical and Electronic Engineering,Electronic, Optical and Magnetic Materials|
|Institution:||The University of York|
|Academic Units:||The University of York > Physics (York)|
|Depositing User:||Repository Administrator York|
|Date Deposited:||20 Jun 2010 19:10|
|Last Modified:||22 Mar 2016 00:01|