The optical response of several magnetic nanoparticle dispersions is studied by angle resolved transmittance at wavelength of 600 nm in zero-field and under an applied magnetic field of 0.1 T, with the purpose of exploring to what extent this could be used as a method of monitoring the colloidal dispersions. In an external magnetic field, magnetic particles will start to order into needle-like structures aligned with the field, which was observed by microscopy. This will change the light scattering caused by the particles. Results showed a clear effect from applying the magnetic field by a dip in the transmitted intensity at angles around 3-5 degrees. The scattering is compared to that of a homogeneous infinite cylinder and theoretical explanations to the effect are discussed. Spectrophotometry at wavelengths between 300-1100 nm is performed and compared with calculations from Kubelka-Munk approximation to give a first characterization of the particle dispersions. Particles used in this project are magnetite, Fe3O4, and maghemite, gamma-Fe2O3, nanoparticles with sizes ranging from 5-250 nm.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-326095 |
| Date | January 2017 |
| Creators | Braesch-Andersen, Anna |
| Publisher | Uppsala universitet, Fasta tillståndets fysik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | UPTEC Q, 1401-5773 ; 17004 |
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