Synthesis and Characterization of Magnetoplasmonic Air-Stable Au@FeCo

Area of Science:

• Materials Science
• Nanotechnology
• Magnetism

Background:

• Iron-cobalt (FeCo) alloys are valuable magnetic nanoparticles.
• Magnetoplasmonics combines magnetic and plasmonic properties in hybrid nanostructures.
• Existing FeCo alloys have limitations in broader applications.

Purpose of the Study:

• To synthesize high-yield, monodisperse spherical FeCo and Au-doped FeCo (Au@FeCo) nanoparticles.
• To characterize the composition, structure, and magnetic properties of the synthesized nanoparticles.
• To explore the potential applications of these magnetoplasmonic metamaterials.

Main Methods:

• Thermal decomposition of iron pentacarbonyl and dicobalt octacarbonyl.
• Addition of gold atoms using triphenylphosphine gold(I) chloride via coprecipitation and delayed addition.
• Characterization using UV-vis, SEM-EDX, HRTEM, XRD, F-AAS, and magnetization measurements.
• Resistance measurements for power loss assessment.

Main Results:

• Au@FeCo nanoparticles with a gold content >2% exhibited a plasmonic peak at 550 nm.
• Elemental mapping confirmed the colocation of Fe, Co, and Au, with Au located in the core.
• Magnetization values ranged from 50 to 150 emu/g depending on gold content.
• Resistance measurements indicated potential for use in electronics.

Conclusions:

• Successful synthesis of Au@FeCo nanoparticles with tunable magnetic and plasmonic properties.
• Demonstrated potential for enhanced spectroscopic detection limits and applications in therapeutics and electronics.
• Established a viable chemical synthesis strategy for developing advanced magnetoplasmonic structures.