PREPARATION AND PROPERTIES OF CARBON-COATED MAGNETIC NANOCRYSTALLITES

Carbon-coated gadolinium carbide nanocrystallites are generated by a p rocess based on the Kratschmer-Huffman carbon-arc method of preparing fullerenes, and a novel magnetic-field-gradient separation technique i s used to separate them. This separation of nanocrystalline byproducts of the carbon arc process is a prerequisite for many of the proposed applications of these materials. While the data presented pertain to G d2C3, this method is generally applicable to any paramagnetic or ferro magnetic compound. Structural characterization by x-ray and electron d iffraction and high-resolution transmission electron microscopy reveal the presence of a single gadolinium-containing (Gd2C3) phase and exce ss carbon. The carbide phase exists as 10-50 nm spherical particles. S QUID magnetometry shows paramagnetic response attributed to Gd3+ ions.