ABSTRACT
The local metallicities of Hf(0.97)Gd(0.03)O(2), Ga(0.97)Gd(0.03)N, Eu(0.97)Gd(0.04)O and EuO films were studied through a comparison of the findings from constant initial state spectroscopy using synchrotron light. Resonant enhancements, corresponding to the 4d â 4f transitions of Eu and Gd, were observed in some of the valence band photoemission features. The resonant photoemission intensity enhancements for the Gd 4f photoemission features are far stronger for the more insulating host systems than for the metallic system Eu(0.96)Gd(0.04)O. The evidence seems to suggest a correlation between the effective screening in the films and the resonant photoemission process.
ABSTRACT
Gd(2)O(3) and Gd-doped HfO(2) films were deposited on p-type silicon substrates in a reducing atmosphere. Gd 4f photoexcitation peaks at roughly 7 and 5 eV below the valence band maximum have been identified using the resonant photoemission of Gd(2)O(3) and Gd-doped HfO(2) films, respectively. In the case of Gd(2)O(3), strong hybridization with the O 2p band is demonstrated, and there is evidence that the Gd 4f weighted band exhibits dispersion in the bulk band structure. The rectifying (diode-like) properties of Gd-doped HfO(2)-silicon and Gd(2)O(3)-silicon heterojunctions are demonstrated.
