Abstract

Magnetic nanoparticles are used in nanotechnologies and biomedical applications, such as drug targeting, hyperthermia, MRI contrasting agents, and bio-separation of compound solutions. Magnetite (Fe3O4) nanoparticles stand to be effective in these roles due to the non-toxic nature of magnetite and its ease of manufacture. To this end, a greater understanding of the magnetic behavior of the individual magnetite nanoparticles is needed when a collection of them is used. This research seeks to discover the local magnetic ordering of ensembles of magnetite nanoparticles at various stages of the magnetization process, temperatures above and below their blocking temperature, and for various particle sizes. We use x-ray circular dichroism and x-ray resonant magnetic scattering (XRMS), which provides information about the magnetic orders in the samples. Here we discuss the modeling of the magnetic scattering data using a one-dimensional chain of nanoparticles in real space as well as an empirical Gaussian packet model in reciprocal space. We find that at low temperature, and field values close to the coercive point, magnetite nanoparticles experience a significant amount of antiferromagnetic ordering that increases with particle size.

Degree

MS

College and Department

Physical and Mathematical Sciences; Physics and Astronomy

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2022-06-07

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd12346

Keywords

magnetite, nanoparticles, magnetic scattering, XRMS, computational modeling

Language

english

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