XPS studies of the Bi-Sr-Ca-Cu-O ceramics at temperatures near T c
1993; American Physical Society; Volume: 48; Issue: 17 Linguagem: Inglês
10.1103/physrevb.48.12989
ISSN1095-3795
AutoresThien‐Phap Nguyen, E. Faulques, P. Molinié,
Tópico(s)Magnetic and transport properties of perovskites and related materials
ResumoCeramic samples of the oxide superconductor ${\mathrm{Bi}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Pb}}_{\mathit{x}}$${\mathrm{Sr}}_{2}$${\mathrm{Ca}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{\mathit{y}}$ with x=0, 0.2, and 0.3 have been prepared and studied by x-ray-photoelectron spectroscopy. A comparison of the Cu 2p, Bi 4f, and O 1s spectra of undoped and doped samples from ambient temperature down to 96 K near the critical temperature suggests the formation of dimer oxygen species in the superconducting state. A mechanism of charge transfer between ${\mathrm{CuO}}_{2}$ and BiO planes is proposed to explain this possibility, which is suggested to be related to the change of the conductivity of the ceramics.
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