Preparation of carbon encapsulated iron nanoparticles with very thin shells by DC arc discharge

Carbon encapsulated iron nanoparticles (CEINPs) with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature (AIT) of 800 °C. The results of high resolution transmission electron microscope (HRTEM), energy dispersive X-ray (EDX) spectroscope, X-ray diffraction (XRD), and X-ray photoelectron spectroscope (XPS) characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5–5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24.7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization (Ms) and coercivity (Hc) of the product B are 107.4 emu/g and 143 Oe, respectively. The formation of the CEINPs in the product B is discussed briefly.