Solvent-surface interactions control the phase structure in laser-generated iron-gold core-shell nanoparticles.

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Chemical synthesis of nanoparticles often involves surface ligands that can interfere with studying solvent-metal interactions.
• Understanding solvent effects is crucial for controlling nanoparticle morphology and properties.

Purpose of the Study:

• To develop a chemical-free synthesis method for FeAu nanoparticles.
• To investigate the influence of different solvents on the internal phase structure and morphology of FeAu nanoparticles.
• To evaluate the properties of the synthesized FeAu core-shell nanoparticles.

Main Methods:

• One-step synthesis of FeAu nanoparticles via pulsed laser ablation of alloy targets in various solvents (acetone, methyl methacrylate, aqueous media).
• Characterization using transmission electron microscopy (TEM) and EDX elemental mapping.
• Analysis of oxidation resistance, magnetic, and optical properties.

Main Results:

• Solvent choice dictates nanoparticle core-shell structure: gold shell/iron core in organic solvents, and iron oxide shell/gold core in aqueous media.
• Core-shell morphology (predominantly Fe@Au or Au@Fe3O4) observed in over 90% of nanoparticles.
• Synthesized Fe@Au nanoparticles exhibit excellent oxidation resistance, good magnetic properties, and plasmonic behavior.

Conclusions:

• Solvent-nanoparticle surface interactions significantly influence phase segregation and elemental distribution in FeAu nanoparticles.
• The developed method offers a route to chemically controlled synthesis of FeAu core-shell nanoparticles.
• FeAu core-shell nanoparticles show promise for applications in imaging due to their stability, magnetism, and plasmonics.