Informace o publikaci
Exploring spin disorder in ferrimagnetic iron oxides using standard DFT and advanced computational methods
| Autoři | |
|---|---|
| Rok publikování | 2025 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Iron oxide nanoparticles are extensively explored for applications in biomedicine, data storage, and spintronic devices, owing to their magnetic behavior and tunable size-dependent properties. While bulk magnetite and maghemite are ferrimagnetic, this long-range magnetic order often diminishes at the nanoscale. The loss of symmetry, reduced coordination environments, and altered bond lengths and angles—particularly in ultrasmall particles with high surface-to-volume ratios—introduce structural and electronic distortions. As a result, the formation of magnetically disordered surface layers has been widely reported by both experimental and computational studies. Configurations involving spin flips 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. This study focuses on the electronic structure of bulk and ultra-small nanoscale iron oxide models exhibiting spin-flipped arrangements, evaluated using standard semilocal density functional theory (DFT) methods and selective approaches beyond standard DFT. A range of exchange-correlation functionals is employed to examine how spin disorder affects key electronic properties such as band structure, band gap width or potential in-gap states. Additionally, machine learning techniques will be explored as a comparative tool to identify the possible spin-flipping phenomena. Altogether the findings aim to identify the most suitable theoretical framework for describing these systems and to support the future design of applications based on their electronic properties. |