X-ray diffraction, transmission electron microscopy, and low temperature SQUID magnetometry were used for analyzing the effect of structural disorders on the magnetic properties of NiFe 2O 4 nanoparticles. By annealing the fine powder at different temperatures, powder samples with different particle sizes were made. Due to the surface disorders, the particle had a core or shell structure. The superexchage coupling, that created a magnetically immobilized region near the surface region with thickness significantly larger than that of the structurally inhomogeneous layer on the surface, was found to be a driving force for the magnetic configuration.
ASJC Scopus subject areas
- Physics and Astronomy(all)