Related Experiment Video
Updated: Aug 26, 2025

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
The Boundary Between Volume and Surface-Driven Magnetic Properties in Spinel Iron Oxide Nanoparticles
Giuseppe Muscas1, Francesco Congiu2, Giorgio Concas2
1Department of Physics, University of Cagliari, Cittadella Universitaria Di Monserrato, S.P. 8 Km 0.700, 09042, Monserrato, CA, Italy. giuseppe.muscas@dsf.unica.it.
Abstract:
Despite modern preparation techniques offer the opportunity to tailor the composition, size, and shape of magnetic nanoparticles, understanding and hence controlling the magnetic properties of such entities remains a challenging task, due to the complex interplay between the volume-related properties and the phenomena occurring at the particle's surface. The present work investigates spinel iron oxide nanoparticles as a model system to quantitatively analyze the crossover between the bulk and the surface-dominated magnetic regimes. The magnetic properties of ensembles of nanoparticles with an average size in the range of 5-13 nm are compared. The role of surface anisotropy and the effect of oleic acid, one of the most common and versatile organic coatings, are discussed. The structural and morphological properties are investigated by X-ray diffraction and transmission electron microscopy. The size dependence of the surface contribution to the effective particle anisotropy and the magnetic structure are analyzed by magnetization measurements and in-field Mössbauer spectrometry. The structural data combined with magnetometry and Mössbauer spectrometry analysis are used to shed light on this complex scenario revealing a crossover between volume and surface-driven properties in the range of 5-7 nm.
More Related Videos
08:13Using Magnetometry to Monitor Cellular Incorporation and Subsequent Biodegradation of Chemically Synthetized Iron Oxide Nanoparticles
Published on: February 27, 2021
07:42Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Related Concept Videos
Magnetostatic Boundary Conditions
Ferromagnetism
Potential Due to a Magnetized Object
The vector...
Diamagnetism
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...