Europhys. Lett.
Volume 68, Number 2, October 2004
Page(s) 282 - 288
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 October 2004
Europhys. Lett., 68 (2), pp. 282-288 (2004)
DOI: 10.1209/epl/i2004-10195-4

Polarized neutron reflectivity on dilute magnetic alloys

J. Swerts1, K. Temst1, C. Van Haesendonck1, H. Fritzsche2, V. N. Gladilin3, V. M. Fomin3 and J. T. Devreese3

1  Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven Celestijnenlaan 200 D, B-3001 Leuven, Belgium
2  Hahn-Meitner-Institut - Glienicker Strasse 100, D-14109 Berlin, Germany
3  Theoretische Fysica van de Vaste Stoffen, Departement Natuurkunde Universiteit Antwerpen - Universiteitsplein 1, B-2610 Antwerpen, Belgium

received 4 March 2004; accepted in final form 25 August 2004

In order to probe the impurity spin magnetization of a thin $\chem{Fe}$ doped (7 at.%) $\chem{Au}$ film, which is near the magnetic percolation limit, we measured the polarized neutron reflectivity of the film. The observed magnetic-field dependence of the magnetization indicates that $\chem{Fe}$ atoms are partially dispersed homogeneously into the $\chem{Au}$ matrix and partially aggregated as clusters with typical size around 1 $\un{nm}$. Our results imply that polarized neutron reflectivity can be used as a sensitive tool to probe the magnetic properties of dilute magnetic alloy films even in the absence of clustering.

75.20.Hr - Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions.
75.30.Cr - Saturation moments and magnetic susceptibilities.
75.30.Gw - Magnetic anisotropy.

© EDP Sciences 2004