ISSN:
1572-9605
Keywords:
Mixed oxides
;
doping
;
electronic structure
;
photoemission
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract Changes induced in the electronic structure of BaTiO3 by substitutions of R = Y, La or Nd for Ba to form the mixed oxides R x Ba1−x TiO3−δ have been investigated using ultraviolet photoelectron spectroscopy. Substitution of formally R+3 ions for Ba+2 leads to the introduction of filled states in the band gap that are shown by resonant photoemission measurements to have significant Ti 3d character, consistent with a Mott-Hubbard insulator description for these oxides. It is suggested that the dominant factor is electron-electron correlation and this leads to the estimatesU∼Δ∼3 eV for this system, whereU is the correlation energy for the 3d and Δ is the charge transfer energy. Changes are observed in the photoelectron spectral shape for these states as a function of increasing substitution in the Nd system and discussed in the context of the opening of the Hubbard gap.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00732271
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