Magnetic properties and dipolar interactions of Fe₃O₄ nanoparticle clusters produced by bottom-up self-assembly

Autor(es)

Fabris, Fernando ; Almeida, Adriele A. ; Ribeiro, Pablo Rafael Trajano ; Pirota, Kleber Roberto ; Muraca, Diego

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS CHEMISTRY C; v. N/A, p. 12-pg., 2025-04-14.

Resumo

Magnetic nanoparticles (MNPs) exhibit unique magnetic behaviors that make them highly applicable in various fields such as biomedical technology, energy, and sensing. This study investigates the magnetic properties and dipolar interactions of Fe3O4 nanoparticle clusters with different average sizes (27.4 nm, 79.2 nm, and 112.9 nm) produced by an emulsion-based bottom-up self-assembly process. The MNPs, with an individual size of 9.8 nm, were organized into clusters, and their collective magnetic properties were explored using detailed DC and AC magnetic studies. We applied a phenomenological mean-field model to describe the magnetic behavior of the clusters, including an increase in blocking temperature, energy barriers, and relaxation dynamics as a function of cluster size. The results indicate a significant influence of dipolar interactions on the energy barriers and magnetic moment dynamics, with larger clusters exhibiting stronger dipolar fields. Our findings provide insights into the interaction between nanoparticle arrangement and magnetic properties, which offers potential for the development of novel magnetic materials for advanced applications. (AU)

• Processo FAPESP: 22/16460-0 - Ferrofluidos para aplicações em escoamento de fluidos viscosos
• Beneficiário: Diego Muraca
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/13678-1 - Propriedades magnéticas em estruturas nanoconfinadas: nanopartículas metálicas e isolantes dopadas com terras-raras produzidas por Laser Ablation e síntese química.
• Beneficiário: Fernando Fabris
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/10581-1 - Fenômenos emergentes em sistemas de dimensões reduzidas
• Beneficiário: Pascoal Jose Giglio Pagliuso
• Modalidade de apoio: Auxílio à Pesquisa - Projetos Especiais
• Processo FAPESP: 21/13592-0 - Magnetolipossomas para liberação controlada e remota de fármacos ativados por meio de campo magnético alternado
• Beneficiário: Adriele Aparecida de Almeida
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado