MAGNETIC CHARACTERIZATION OF SELF-ASSEMBLED ONE-DIMENSIONAL NETWORKS OF MAGNETIC NANOPARTICLES

Abstract: In this thesis, a magnetic study of two dierent arrangements of Fe3O4 nanoparticles is presented. The nanoparticles are generated using an aerosol technique and guided onto a substrate. The rst sample was produced by guiding the nanoparticles onto the substrate using an electric eld, resulting in large clusters of randomly oriented Nanoparticle (NP). The second sample was created by also applying a magnetic eld which resulted in the formation of self-assembled networks of one-dimensional Nanowire (NW) made up from individual nanoparticles. To measure the magnetic properties of the samples a Supercondunting Quantum Interference Device (SQUID) is used. Magnetization curves measured at 300 K and 1:8 K show a dierence in the magnetization behavior for the two samples and an increase in the remanent magnetization of 50% for the self-assembled structures. The results are interpreted based on the Stoner-Wohlfarth model, and the shortcomings of applying this model to our systems are discussed.