In this paper, we present photoemission experiments on the hole-doped Haldane chain compound Y2-xSrxBaNiO5. By using the photon energy dependence of the photoemission cross section, we identified the symmetry of the first ionisation states (d type). Hole doping in this system leads to a significant increase in the spectral weight at the top of the valence band without any change in the vicinity of the Fermi energy. This behavior, never observed in other charge transfer oxides, could result from the Ni-3d-O-2P hybridization enhancement due to the shortening of the relevant Ni-O distance with doping. (C) 2002 Elsevier Science B.V. All rights reserved.
|Numero di pagine||6|
|Rivista||NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS|
|Stato di pubblicazione||Pubblicato - 2003|
- charge transfer insulator
- hole doping
- photoemission spectroscopy
- strongly correlated systems