Abstract
Nanoparticles of (hematite) typically have the sublattice magnetization directions in the hexagonal (001) plane below the Néel temperature. By use of Mössbauer spectroscopy we have found that for agglomerated particles the sublattice magnetization may be rotated of the order of 15° out of plane, depending on the particle size. The spin rotation can be explained by exchange interaction between neighboring particles with nonparallel (001) planes. The results imply that interparticle interactions can lead to spin directions deviating from the easy axis defined by the magnetic anisotropy.
- Received 14 July 2004
DOI:https://doi.org/10.1103/PhysRevLett.94.027202
©2005 American Physical Society