Characterization and Magnetic Properties of Cobalt Nano-Particles Prepared by Metal Vapor Synthesis Technique

摘要

The metal vapor synthesis technique was employed to prepare Co nanoparticles. The characteristics and properties ofthe particles were studied by transmission electron microscopy, X-ray diffraction, temperature-programmed desorption,chemisorption and magnetic measurements. The experimental results showed that the particle size of Co powdersdepended on the initial Co concentration in the toluene matrix, reaching average crystallite diameter of 1.5 nm for thehighest concentration (6.4 at. pct) investigated. The particles with size of 10 nm exist, due to the agglomerates ofmicrocrystallites. The Co particles were surrounded by a thin carbonaceous layer formed due to toluene decompositionon cocondate melt-down and subsequent warming to room temperature. The carbonaceous layer was composedprimarily of C1 fragments. The Co powders demonstrated ferromagnetic behavior.