The effect of surface plasmonic resonances on magneto-plasmonic spherical core-shell nanocomposites

Abstract

 In this study, the effect of plasmon resonance on magneto-plasmonic  spherical core-shell nanocomposite enclosed in a dielectric host medium is theoretically investigated by applying electrostatic approximation (esa) and Maxwell-Garnet effective medium theories to obtain magneto-optical parameters such as; effective electric permittivity and magnetic permeability as well as the corresponding extinction cross-sections. Likewise, for a fixed size of QDs (of radius  nm) numerical analysis was performed to determine the plasmonic resonance effect by varying the parameters such as the metal fraction (β) and the dielectrics (ε_h) of the host medium on the magneto-plasmonic nanostructures (nss). The results depict that graphs of absorption, scattering, and extinction cross-sections as a function of wavelength have two positions of resonance peaks. The first set of peaks are in the ultraviolet (uv) and the second located in visible regions. These peaks originated from the strong coupling between a regular periodic vibrations of surface plasmons of silver (Ag) with the excitonic state of the dielectric/semiconductor at the internal ( ) and external (Ag/host) interfaces. As β increases, the absorption and scattering cross-sections are blue-shifted in the first peak and red shifted the second set of peaks. Similarly, as ε_h increases or as β decreases, the sets of resonance peaks for extinction cross-section gets enhanced; while keeping one of these parametric quantities fixed at once. The resulting surface plasmon resonance effect might be utilized in a variety of applications that combines both the plasmonic and magnetic core-shell nanostructures ranging from UV to Visible spectral regions.