57 research outputs found
Variation of strong correlation effects in A-site ordered perovskites CaCu3Ti4-xRuxO12: Photoemission and inverse photoemission studies
We have systematically studied the strong correlation effects in A-site
ordered perovskites CaCu3Ti4-xRuxO12 (x = 0, 1, 3.5, 4) by using photoemission
and inverse photoemission spectroscopies. In x = 0, 1, 3.5, the peak positions
of the strongly correlated Cu 3d states around -3.8 eV and Ti 3d states around
3.6 eV little change. On the other hand, in x = 4, the Cu 3d states is observed
around -2.5 eV. These indicate that Ti plays an important role to retain the
strong correlation effects. In addition, the multiplet structures of Cu 3d
final states from -8 to -15 eV become weak as Ru increases, indicating the
reduction of the localized characters of Cu 3d states. At the Fermi level, we
observe the absence of spectral weight in x = 0, 1 and the development of Ru 4d
in-gap states between the Cu 3d and Ti 3d peaks in x = 3.5, 4, which give rise
to the metal-insulator transition between x = 1 and x = 3.5.Comment: 12 pages, 3 figure
Phytoplankton assemblage of the Merambong Shoal, Tebrau Straits with note on potentially harmful species
Investigations of body scales in twelve <em>Heterocapsa</em> species (Peridiniales, Dinophyceae), including a new species <em>H. pseudotriquetra</em> sp. nov.
Wide distribution of a domoic acid-producing diatom <em>Nitzschia navis-varingica</em>. Abstracts, Xth International Conference on Harmful Algae, 21-25 oktober 2002, St. Pete Beach, Florida
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