Speaker
Description
Ferrimagnetic iron oxides such as magnetite or maghemite find many applications in magnetic recording, spin-based electronics and biomedicine. However, when reduced to the nanoscale, their long-range spin ordering often collapses, giving rise to surface-driven magnetic disorder. This disruption originates from broken interactions, symmetry and reduced atomic coordination at facets and edges of the nanoparticles, leading to the stabilization of spin-flipped states. Configurations involving magnetic disorder at the surface reduce the net magnetic moment and may correspond to metastable, energetically accessible states. Interestingly, magnetic disorder has also been associated with enhanced T₁ relaxation times in MRI, pointing to a potential connection between local spin structure and biomedical functionality.
In this study, we analyse electronic structure of bulk and nanoscale models of iron oxides in both ferrimagnetically ordered and spin-disordered states using Density Functional Theory (DFT) and selective approaches beyond standard DFT.
