AGGLOMERATION EFFECTS IN FePt NANOPARTICLES ON Si SUBSTRATES STUDIED BY SMALL ANGLE NEUTRON SCATTERING AND MAGNETOMETRY

摘要

FePt nanoparticles in an organic binder are currently attracting considerable attention both as systems in which to study physics on the nano-scale and for potential applications [1]. One of the most promising applications for high anisotropy nanoparticles is as a recording medium, due to the fact that as-deposited FePt nanoparticles have been created with diameters of 4nm and an extremely narrow size distribution σ < 5%. In order to create the high anisotropy L1{sub}0 phase of FePt the nanoparticles are usually annealed at temperatures above 500°C, typically for times of 30mins. Such high temperatures are likely to have a deleterious effect on the organic binder and can lead to undesired particle agglomeration, giving rise to clusters of the individual particles. In this work we investigate particle sizes and magnetic properties of FePt nanoparticles to determine if annealing at high temperatures for short times leads to the desired magnetic properties with reduced agglomeration.