Electronic structure of (formula presented) comparison between substitutional and vacancy doping

Physical Review B - Condensed Matter and Materials Physics

Volumn 59, Issue 3, 1999, Pages 1815-1818

  Yokoya, T ^a   Sato, T ^a   Fujisawa, H ^a   Takahashi, T ^a   Chainani, A ^b   Onoda, M ^c  

^a TOHOKU UNIVERSITY   (Japan)

^b INSTITUTE FOR PLASMA RESEARCH   (India)

^c UNIVERSITY OF TSUKUBA   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 13744260523     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.59.1815     Document Type: Article

References (27)

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21. For the XAS spectra, the midpoint of the leading edge in the metallic samples can be taken to be (Formula presented) In Fig. 22, it is located at a 530.4-eV photon energy. This seems to imply that the undoped case also has a small finite DOS at (Formula presented) which is due to the poorer resolution (∼1 eV) in the XAS.
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24. If the model DOS is convoluted with a Gaussian for the resolution and compared with the experiment, the experimental result has a slightly higher intensity than the simulation in the immediate vicinity of (Formula presented) Thus the gap is not a clear gap, and is consistent with the resistivity measurements which do not show a clear activated gap but show a variable range hopping. We note that the optical reflectivity measurements also give a similar result for the gap as obtained by us for (Formula presented) (∼100 meV) (Ref. 12).
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27. Note also that the reduced intensity near (Formula presented) in UPS for (Formula presented) is compensated for by the increased intensity in XAS compared to the (Formula presented) spectra. The relative DOS at (Formula presented) was obtained by two independent normalization methods, using (1) the area under the curve or (2) the peak height of the lower Hubbard band. Both results are nearly identical to one another.