Comparison of light scattering from self assembled array of nanoparticle chains with cylinders

Abstract

We use a magnetic field to generate array of linear chains of magnetic nanoparticles in a magnetically polarizable nanofluid. The scattered patterns by these chains are described by electromagnetic wave scattering from an infinite cylinder. Comparison of the incident angle dependent scattered patterns from the linear chains of nanoparticles and macroscopic cylinders show a striking similarity. But, unlike the diffraction fringes of different orders observed on the cone of scattered light from macroscopic cylinder, the observed scattered cone from the field induced nanostructures is diffused. The observed optical patterns for micron sized cylinder are a simultaneous manifestation of both scattering and diffraction due to the interaction of light with cylindrical surfaces, whereas for nanoparticle chains it is mainly due to scattering. The diameters of the cylinders are precisely calculated from the best fit on the experimental diffraction intensity pattern. These results are important for better understanding of self assembled nanostructures for applications.