Influence of dipolar interactions on the magnetic properties of superparamagnetic particle systems
Abstract
Magnetic effects caused by dipolar interactions in single-domain magnetic ensembles at finite temperatures are described. A modified superparamagnetic approach based on the mean field theory and random anisotropy model has been developed to describe the magnetization curves of nanoparticle assemblies. The model was used to fit experimental zero-field-cooled and field-cooled magnetization curves in Fe3O4 nanoparticles embedded in paraffin. The fitting parameters were based on structural properties of the materials and the strength of the interactions between nanoparticles. The model provides a quantitative description of the effects of the nanoparticle interaction with good agreement with the experiment. In addition, the model was adapted to describe magnetic properties of a NiFe thin film patterned into a nanodot array, showing potential to be used as a framework to predict magnetic interaction effects in high-density 2D arrays such as bit patterned media.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 04, 2019
- Source ID
- 10.1063/1.5125595
Entities
People
- C. A. Ross
- F. Fabris
- Kun-hua Tu
- Wallace C Nunes
Organizations
- Coordenação de Aperfeicoamento de Pessoal de Nível Superior
- Defense Advanced Research Projects Agency
- Fluminense Federal University
- Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
- Massachusetts Institute of Technology
- National Council for Scientific and Technological Development
- National Science Foundation