Photoemission and x-ray-absorption study of misfit-layered (Bi,Pb)-Sr-Co-O compounds: Electronic structure of a hole-doped Co-O triangular lattice

Takashi Mizokawa, L. H. Tjeng, P. G. Steeneken, N. B. Brookes, I. Tsukada, T. Yamamoto, K. Uchinokura

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We present a photoemission and x-ray-absorption study of the misfit-layered (Bi,Pb)-Sr-Co-O compounds which have a Co-O triangular lattice with a mixed valence of Co3+ and Co4+. The valence-band photoemission as well as the O 1s and Co 2p x-ray absorption spectra indicate that Co3+ and Co4+ have the low-spin t2g6 and t2g5 configurations, respectively. The angle-resolved photoemission spectra show that the dispersion of the t2g feature is very small compared to its width at each angle, suggesting that the electron-lattice coupling energy is much larger than the kinetic energy of the t2g electrons and that the carriers in the Co-O triangular lattice are essentially polarons formed by Co4+ in the nonmagnetic Co3+ background.

Original languageEnglish
Article number115104
Pages (from-to)1151041-1151047
Number of pages7
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number11
Publication statusPublished - 2001 Sep 15
Externally publishedYes


ASJC Scopus subject areas

  • Condensed Matter Physics

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