Investigating of LSPR spectra on a hybrid Fe₃O₄-Au within core-shell structure

In this study, we have investigated the tunability of localized surface plasmon resonance (LSPR) spectra of the magneto-plasmonic system composed of Au-coated Fe₃O₄ (Fe₃O₄@Au) by public optical simulation, MNPBEM based on boundary element method calculation. The magneto-plasmonic system is modeled nanorod core-shell structure with three different core's aspect ratio: 2.3, 4.3, and 6.3. The nanoparticle was immersed in water (1.33+0i). Then, we applied the electromagnetic field in parallel and perpendicular to the long axis of nanorod. Interestingly, the peak of LSPR spectra Fe₃O₄@Au shows blue-shifted at gold thickness toward around ∼50 nm and as the gold-shell keep growing, a red-shifted can be occurred on greater than ∼50 nm of thick gold-shell. The peak of LSPR spectra shows to shift to lower wavelength or blue-shift and produce narrow width spectra. Based on the result, we believe our observation can be utilized for tuning LSPR spectra from visible range to near-infrared such as photocatalysis application and biosensing with well-controlled of thicknesses.