Photoemission studies of BaPb1?xBixO3 and Ba1?yKyBiO3 crystals

Spectroscopic and magnetic behavior of xNd2O3(1−x)(3Bi2O3·PbO) glasses

“…The BE values obtained from the high resolution XPS spectra of the Bi 4f photoelectrons, shown in Table 1, are close to those of 158.63 eV for Bi 4f 7=2 state and 164.52 eV for Bi 4f 5=2 state previously reported for other bismuth oxide compounds [23][24][25]. The BE and FWHM data for the Bi 4f photoelectrons present the same evolution with respect to x as that observed for the Pb 4f photoelectrons (see Table 1).…”

Analysis of the interfacial characteristics of BiVO4/metal oxide heterostructures and its implication on their junction properties

“…In addition, the distinction between Bi 3+ and Bi 5+ in Bi4f photoelectron spectra can be vague, as was observed for compounds with mixed bismuth valence states such as BaBiO3. [73][74][75] For both NiO and CoOx a similar Schottky-type barrier height between 1.0-1.1 eV is obtained. Similarly, in our previous work we obtained a Schottky-type barrier height of 1.1 eV for the BiVO4/RuO2 interface.…”

Experimental and theoretical study of the electronic structure of single-crystal BaBiO3

“…Therefore, due to the strong Coulomb interaction between this 1/3 hole and the O 1s core-hole, created through the XPS, one would generally expect to see a main peak and a strong satellite structure in the oxygen 1s XPS spectrum. However, while many find such structure, they assign it merely to the surface contamination [28,31,34] and avoid explaining the oxygens' electronic role in the spectrum. Moreover, on the other hand, some assign this structured peak to the different oxidation states of the oxygens without perhaps the required diligent cleaning procedure [30].…”

“…Band structure calculations do not find a significant charge transfer between the two bismuth sites [4,26,27]. X-ray photoemission measurements also don't give conclusive evidence for two different bismuth oxidation states [28][29][30][31]. Doubling the unit cell by the structural "bond-disproportionation" has been proposed as an alternative insulating mechanism by opening up a gap similar to the Peierls distortion mechanism but for a three-dimensional structure [4,32,33].…”

“…This is a very different description electronically and hasn't yet been accepted unanimously by the community [7]. One objection is that the evidence for holes on the oxygens should clearly appear in experiments like O 1s x-ray photoemission; however, the existing results have not been conclusive [27,28,30,31,34]. In this work, we try to address this controversy by studying the electronic structure of oxygen anions experimentally with x-ray spectroscopy measurements and theoretically using exact diagonalization cluster calculations.…”