LASER-ABLATION OF C-60-LA2O3 MIXTURE - A NEW ROUTE FOR TRAPPING METAL ATOMS INSIDE A FULLERENE CAGE

The reaction of excimer laser (XeCl, 308 nm ) vaporized and excited fullerene C-60 With La was carried out in a mixture of C-60 and La2O3. The reaction products La@C-60, La@C-60-2n and La@C-60+2m were identified by a reflectron type time-of-flight mass spectrometer (RTOFMS). This work provides a first experimental evidence of endohedral metallofullerene formation by letting a La atom penetrate into the C-60 cage through a sort of `window' mechanism.