Low-energy electron induced decomposition of Fe(CO) 5 adsorbed on Ag(111)

Abstract

The low-energy electron induced decomposition of monolayer and multilayer Fe(CO) 5 on a Ag(111) surface was examined with temperature programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED). In the absence of electron bombardment, Fe(CO) 5 thermally desorbs from Ag(111) in monolayer (181 K) and multilayer (170 K) desorption states with minimal decomposition. Low-energy (3–132 eV) electron bombardment converts adsorbed Fe(CO) 5 into Fe x (CO) y clusters. These new species are much less susceptible to electron induced decomposition than adsorbed molecular Fe(CO) 5. Fe x (CO) y clusters thermally decompose near 330 K, liberating gas phase CO and depositing Fe x particles on the Ag(1 surface. Little C or O is present on these Fe x clusters. The Fe x species do not exhibit metallic character, based on their inability to subsequently adsorb CO. The total cross section for the electron induced decomposition of Fe(CO) 5 adsorbed on Ag(111) is (1–14) × 10 −16 cm 2 for electrons in the energy range 3–132 eV, comparable to the gas phase Fe(CO) 5 cross section for electron-induced processes.