TY  - JOUR
AU  - Kettner, Miroslav
AU  - Duchoň, Tomáš
AU  - Wolf, Matthew J.
AU  - Kullgren, Jolla
AU  - Senanayake, Sanjaya D.
AU  - Hermansson, Kersti
AU  - Veltruská, Kateřina
AU  - Nehasil, Václav
TI  - Anion-mediated electronic effects in reducible oxides: Tuning the valence band of ceria via fluorine doping
JO  - The journal of chemical physics
VL  - 151
IS  - 4
SN  - 1089-7690
CY  - Melville, NY
PB  - American Institute of Physics
M1  - FZJ-2019-04075
SP  - 044701 -
PY  - 2019
AB  - Combining experimental spectroscopy and hybrid density functional theory calculations, we show that the incorporation of fluoride ions into a prototypical reducible oxide surface, namely, ceria(111), can induce a variety of nontrivial changes to the local electronic structure, beyond the expected increase in the number of Ce3+ ions. Our resonant photoemission spectroscopy results reveal new states above, within, and below the valence band, which are unique to the presence of fluoride ions at the surface. With the help of hybrid density functional calculations, we show that the different states arise from fluoride ions in different atomic layers in the near surface region. In particular, we identify a structure in which a fluoride ion substitutes for an oxygen ion at the surface, with a second fluoride ion on top of a surface Ce4+ ion giving rise to F 2p states which overlap the top of the O 2p band. The nature of this adsorbate F−–Ce4+ resonant enhancement feature suggests that this bond is at least partially covalent. Our results demonstrate the versatility of anion doping as a potential means of tuning the valence band electronic structure of ceria
LB  - PUB:(DE-HGF)16
C6  - pmid:31370552
UR  - <Go to ISI:>//WOS:000478625700040
DO  - DOI:10.1063/1.5109955
UR  - https://juser.fz-juelich.de/record/864241
ER  -