AUGER-SPECTROSCOPY OF A FULLERITE FILM ON AN IRIDIUM SURFACE

A technique has been developed for producing a flux of C60 molecules i n ultrahigh vacuum and has been used to grow fullerite films on iridiu m. The Auger spectrum of carbon from the fullerite has been obtained a t high resolution (DELTAE/E less than or similar 0.1 %). This spectrum has a characteristic shape which is different from the spectra of dia mond, graphite single crystals, polycrystalline graphite, metal carbid es, and SiC. The C60 molecules begin to desorb from the fullerite at g reater-than-or-equal-to 600 K, and from the iridium at greater-than-or -equal-to 900 K; the flux depends weakly on T. At greater-than-or-equa l-to 1200 K the C60 molecules effectively decay in the adsorbed film o n the Ir, forming graphite.