Plasma methods can produce unique metastable materials, which are unavailable by conventional techniques. In particular, the magnetic materials (e.g. applied in information storage) have been of great interest and it is believed that ferromagnetic transition metal crystallites encapsulated in carbon shells might be used in this area. In such materials, the enclosed metal particles would retain their magnetic moments while being chemically and magnetically isolated from their neighbors.
In this paper, the formation of novel nanostructures was achieved by DC arcing of carbon anodes filled with Nd2Fe14B material. The influence of operational parameters (e.g. pressure, sublimation rate, anode composition) on the product characterization was studied. The optical emission spectroscopy was carried out on-line to determine the temperature and C2 radial concentration fields. The solid products were analyzed by using different techniques. Fullerenes content was evaluated spectrophotometrically. The morphology of the nanostructures was studied by electron microscopy (SEM, HRTEM). The formation of carbon encapsulates was confirmed. Starting material and discharge products were subjected to magnetic measurements. The hysteresis loops proved that the processing affected the physical properties.
This work was supported by the Committee for Scientific Research (KBN) through the Department of Chemistry, Warsaw University under Grant No 4T08D 021 23.