Issue
EPL
Volume 85, Number 4, February 2009
Article Number 47003
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/85/47003
Published online 18 February 2009
EPL, 85 (2009) 47003
DOI: 10.1209/0295-5075/85/47003

Porosity-induced spin disorder in nanocrystalline inert-gas–condensed iron

A. Michels1, M. Elmas1, F. Döbrich1, M. Ames1, J. Markmann1, M. Sharp2, H. Eckerlebe2, J. Kohlbrecher3 and R. Birringer1

1   Technische Physik, Universität des Saarlandes - Saarbrücken, Germany, EU
2   GKSS Forschungszentrum - Geesthacht, Germany, EU
3   Paul Scherrer Institute - CH-5232 Villigen PSI, Switzerland

andreas.michels@mx.uni-saarland.de

received 17 November 2008; accepted in final form 27 January 2009; published February 2009
published online 18 February 2009

Abstract
We report magnetization and magnetic neutron scattering measurements on nanocrystalline Fe which was prepared by means of the inert-gas condensation technique. Depending on the compaction pressure applied during the synthesis procedure (0.5–1.8 GPa), the resulting Fe samples contain porosity with volume fractions between about 20–35%. We provide evidence that the spin disorder which is associated with porosity has a strong influence on magnetic properties, and it gives rise to a characteristic clover-leaf–shaped angular anisotropy in the elastic-magnetic-scattering cross-section.

PACS
75.50.Tt - Fine-particle systems; nanocrystalline materials.
75.25.+z - Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.).
61.05.fg - Neutron scattering (including small-angle scattering).

© EPLA 2009