Purification and Characterization of Carbon Nanotubes and Prospects for the Formation of Magnetic Semiconductor via Iron Incorporation

Abstract

This article reports the synthesis of iron (Fe) encapsulated carbon nanotubes (CNTs) prospective to the formation of magnetic semiconductors, by the arc discharge method. Morphology of the samples was studied from transmission electron microscope (TEM) and scanning electron micrograph (SEM) imaging. The data was recorded by x-ray diffractometer (XRD) and energy dispersion x-ray (EDX) equipments for the identification of the sample constituent. TEM images of metal added samples indicate that defects are completely removed after mono acidic treatment and open air oxidizing at 400°C for 15 minutes leaving nano sized carbonaceous skeins attached on the surface of carbon nanotubes and catalyst particles encapsulated. This formation is recognized as a phenomenon at certain temperature limit. From the SEM analysis, a new phenomenon of spherical structure with diameter nearly 15 µm to which bundles of CNTs and carbonaceous impurities are attached is observed. EDX examination shows that the carbon weight % is dominating the composition along with oxygen and iron, perhaps, forming FeO during the reaction. It is also revealed from XRD analysis, indicating success in metal incorporation. This envisages that there would be formation of magnetic semiconductors, as it can be verified with further experiments, where iron ions may take carbon cites in the CNTs with semiconducting behavior and iron filling otherwise.