https://doi.org/10.1140/epjb/e2004-00306-7
Surface effects in α-Fe2O3 nanoparticles
1
Centro Atómico Bariloche, 8400 S.C. de Bariloche, RN, Argentina
2
ISM-CNR, Area della Ricerca di Roma, C.P. 10, 00016 Monterotondo,
Roma, Italy
Corresponding author: a zysler@cab.cnea.gov.ar
Received:
20
February
2004
Published online:
12
October
2004
The magnetic properties of 5 nm 
-Fe2O3 nanoparticles have
been investigated by magnetization measurements on a sample consisting of
homogeneously dispersed, non-interacting, nanoparticles in a polymer matrix.
The results indicate that the magnetic properties are mainly determined by
surface effects, which manifest themselves in high coercive field, high
irreversibility field and shifted hysteresis loop, after field cooling.
These effects come from surface anisotropy and exchange anisotropy, due to
the coupling between the disordered surface magnetic structure, with
multiple spin configurations, and the core antiferromagnetically ordered
structure.
PACS: 75.50.Tt – Fine-particle systems; nanocrystalline materials / 75.75.+a – Magnetic properties of nanostructures / 75.70.Rf – Surface magnetism / 75.50.Ee – Antiferromagnetics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004
