Thermal Plasma Synthesis of Fe-Co Alloy Nanoparticles

Abstract

FeCo nanoparticles are synthesized in a radio frequency (RF) plasma torch from metal powder precursors and simple gases. The first precursor consists of pre-alloyed FeCo powder; the second precursor is a mixture of elemental Fe and Co powders. A protective carbon coating on the particles is achieved by injection of acetylene gas into the plasma. X-ray diffraction reveals phase purity, low carbon concentration, and minimal oxidation. Analytical electron microscopy is used to examine the nanocomposite morphology and composition of individual nanoparticles. Both synthesis routes produce alloy product, but nanoparticles produced from pre-alloyed precursors exhibit smaller variations in Fe/Co ratio than particles produced from elemental powders.