UNIGE document Scientific Article
previous document  unige:114364  next document
add to browser collection

Infrared optical conductivity of the Nd-Ce-Cu-O system

Lupi, S.
Calvani, P.
Capizzi, M.
Maselli, P.
Published in Physical Review. B, Condensed Matter. 1992, vol. 45, no. 21, p. 12470-12477
Abstract The reflectivity of seven Nd₂₋ₓCeₓCuO₄ single crystals has been measured at room temperature between 0.005 and 3 eV for 0≤x≤0.21. At x=0, four transverse and longitudinal Eu phonon modes have been determined. Two bands have been also identified at 1.6 eV and at 2.8 eV, which lose their intensity with doping. Such intensity is transferred to the well-known Drude and midinfrared contributions, and to a band at ∼0.1 eV, which can be attributed to oxygen vacancies. At the insulator-to-metal transition, the Drude term abruptly increases, the 1.6-eV band vanishes. An overall strong similarity with the closing of the optical gap in highly doped semiconductors, is found. The reflectivity of a reduced sample with x=0.07 suggests that the midinfrared band may not originate from oxygen vacancy states. Present results are compared with predictions of different theoretical models.
Full text
Article (Published version) (506 Kb) - document accessible for UNIGE members only Limited access to UNIGE
Other version: https://link.aps.org/doi/10.1103/PhysRevB.45.12470
(ISO format)
LUPI, S. et al. Infrared optical conductivity of the Nd-Ce-Cu-O system. In: Physical Review. B, Condensed Matter, 1992, vol. 45, n° 21, p. 12470-12477. doi: 10.1103/PhysRevB.45.12470 https://archive-ouverte.unige.ch/unige:114364

212 hits

0 download


Deposited on : 2019-02-15

Export document
Format :
Citation style :