Abstract

Small-angle neutron scattering with polarization analysis reveals that Fe3O4 nanoparticles with 90 Å diameters have ferrimagnetic moments significantly reduced from that of bulk Fe3O4 at 10 K, nominal saturation. Combined with previous results for an equivalent applied field at 200 K, a core-disordered shell picture of a spatially reduced ferrimagnetic core emerges, even well below the bulk blocking temperature. Zero-field cooling suggests that this magnetic morphology may be intrinsic to the nanoparticle, rather than field induced, at 10 K.

Publisher

AIP Publishing

Publication Date

1-1-2010

Publication Title

Journal of Applied Physics

Department

Physics and Astronomy

Document Type

Article

DOI

10.1063/1.3358049

Keywords

Magnetic nanoparticles, Polarized neutron scattering

Document Version

published

Language

English

Format

text

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