The interaction between oxygen and the Fe/Cu(100) interface has been studied as a function of both the iron thickness and the oxygen exposure by means of UPS and XPS spectroscopies. A careful analysis of the Fe 2p spectra has shown that upon exposing Fe thin films (0.5-10 ML) to 10(4) L of oxygen there is always the formation of Fe2O3. Instead, when a copper surface containing 0.5 and 1 ML of iron has been exposed to increasing amounts of oxygen (1-10(4) L), the presence of both Fe2+ and Fe3+ is evident in the middle stage of the oxidation. The UPS spectra have shown a strong decrease of the Cu3d features when the Fe/Cu interface has been exposed to oxygen, even for very thin Fe films (0.5-1 ML). This behaviour can be interpreted in terms of a sizeable decrease of the mean free path of low energy valence band electrons when the iron film is oxidized with respect to that observed in metallic iron films.
OXIDATION OF THE FE/CU(100) INTERFACE
LOZZI, Luca;PASSACANTANDO, MAURIZIO;
1995
Abstract
The interaction between oxygen and the Fe/Cu(100) interface has been studied as a function of both the iron thickness and the oxygen exposure by means of UPS and XPS spectroscopies. A careful analysis of the Fe 2p spectra has shown that upon exposing Fe thin films (0.5-10 ML) to 10(4) L of oxygen there is always the formation of Fe2O3. Instead, when a copper surface containing 0.5 and 1 ML of iron has been exposed to increasing amounts of oxygen (1-10(4) L), the presence of both Fe2+ and Fe3+ is evident in the middle stage of the oxidation. The UPS spectra have shown a strong decrease of the Cu3d features when the Fe/Cu interface has been exposed to oxygen, even for very thin Fe films (0.5-1 ML). This behaviour can be interpreted in terms of a sizeable decrease of the mean free path of low energy valence band electrons when the iron film is oxidized with respect to that observed in metallic iron films.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
