SCATTERING CROSS-SECTION RESPONSE FROM A GROUP OF COATED SPHERICAL METAL NANOPARTICLES

• Main Author: Muslimin, Ikhwanul
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/48997
• Institution: Institut Teknologi Bandung

The development of nano technology to manipulate light rays progresses rapidly. One way to manipulate light beams is by scattering light off a certain systems. From the many geometries of the system that have been studied, one of the interesting case is spherical geometry. In this Final Project research, Mie scattering theory is used for a group of coated metal spheres. The Mie theory expands certain fields in the basis of vector spherical harmonics (VSH) and use the addition theorem to resolve field interactions between spheres. Through this formulation, the scattering, extinction and absorption cross-sections can be obtained. The formulation that has been made is used to compare the scattering cross-section between a group of coated spherical metal nanoparticles and a group of spherical nanoparticles with Maxwell-Garnett effective permittivity and numerical methods (surface integral). Using several coated sphere configurations and variations in spacing between the spheres, variations in outer layer material, and variations in the number of spheres it is found that the effective permittivity of Maxwell-Garnett shows a good scattering cross-sectional response for large spacing between the spheres because the identity of its constituents is still dominant. If the distance between the spheres is reduced, the identity of the constituents is weakened, and the system behave as a larger scatterer which causes the resonant frequency to experience red-shift.