Lucien Fiermans

Observation of surface phonons on the (001) and (100) surfaces of anatase minerals

Abstract The surface properties of TiO2-anatase are of great importance in chemical technology because this material is frequently used as a support for oxide catalysts. In the present work, surface phonons were observed on the (001) and (100) surfaces of anatase minerals by means of HREELS. After comparison with theoretical values and infrared data a preliminary assignment of the observed modes was achieved.

Resonant electron emission in heavily oxidized lanthanum

Abstract Electron-excited 4d Auger spectra of La and heavily oxidized La have been measured. A distinct peak, appearing just above the 4d excitation threshold in heavily oxidized La, is tentatively assigned to an interatomic autoionization process accompanying the 4d → 4f giant resonance excitation. The absence of a similar peak in La metal is explained as being due to the very weak coupling between the 4f level and the metal valence band.