Selective encapsulation of the carbides of yttrium and titanium into carbon nanoclusters

Characterization of the arc-discharge deposits at the cathode from anodes containing yttrium oxide and titanium by transmission electron microscopy and x-ray diffraction shows different results with respect to an encapsulation of the metal carbides into carbon clusters. Yttrium carbide is encapsulated into carbon nanoclusters in a crystalline phase. The formation of titanium carbide, on the other hand, preempts the formation of the carbon - carbon bonds necessary to form the carbon cages, so that only titanium carbide clusters are observed. Thermodynamic data support the interpretation of the results.