Size-dependent optical properties and thermal response of Fe/Co/Ni@Au and Fe/Co/Ni@Ag core-shell nanospheres

Abstract

In this work, Mie theory is employed to study the opto-thermal response of magneto plasmonic Fe/Co/Ni@Au and Fe/Co/Ni@Ag core-shell nanostructures of different sizes in the presence of dielectric media (i.e., water) is investigated numerically. The optical and thermal characteristics from the Fe, Co, and Ni as core material with noble metal Au and Ag as coating (shell) material are susceptible to being well-tuned by controlling the dimensions of both core and shell, based on the research being conducted at the moment. The SPR wavelength spectra of magnetic core Fe /Co /Ni (radii ranging from 10–40 nm) with Au and Ag coating (fixed shell thickness of 5, 10, and 15 nm), nanostructures are tuned from 231–528 nm and 364–420 nm, respectively. The maximum temperature obtained near the surface of Fe/Co/Ni@Au and Fe/Co/Ni@Ag nanospheres with the optimized size is 2.09℃ / 2.09 ℃ / 2.23 ℃ and 2.30 ℃ / 2.33 ℃ / 2.33 ℃, respectively. It can be observed that the surface plasmon resonance (SPR) is located in the vicinity of the ultraviolet (UV) and infrared (IR) domains of the electromagnetic (EM) spectra. The temperature rise noticed in the nanoparticle (NP) has been attributed to enhanced absorbance efficiency.