Optical Absorption in La2−xSrxCuO4 Epitaxial Thin Films

  • M. Suzuki
Conference paper
Part of the Springer Series in Solid-State Sciences book series (SSSOL, volume 89)


An experimental study on optical absorption is described for La2− x Sr x Cu4 (x = 0 ~ 0.36) c-axis oriented epitaxial films. In addition to the fundamental absorption corresponding to the energy gap of 2 eV, an anomalous absorption band is seen in the optical transmission spectra. This absorption, the intensity of which increases with Sr doping, implies Sr doping induces electronic states within the gap of La2CuO4. With further Sr doping, the density of states forms a band about 1 eV wide and centered at about 0.5 eV above the top of the original valence band. This emerging density of states within the gap is totally at variance with the conventional rigid band model, and seems to be inherent to the high T c superconductors.


Fermi Level Optical Absorption Doping Level Electron Energy Loss Spectroscopy Epitaxial Film 
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  1. [1]
    J. G. Bednorz and K. A. Müller, Z. Phys. B 64, 189 (1986).CrossRefADSGoogle Scholar
  2. [2]
    A. Fujimori, E. Takayama-Muromachi, Y. Uchida, and B. Okai, Phys. Rev. B 35, 8814 (1987)CrossRefADSGoogle Scholar
  3. A. Fujimori, E. Takayama-Muromachi, Y. Uchida, Solid State Commun. 63, 857 (1987).CrossRefADSGoogle Scholar
  4. [3]
    N. Nücker, J. Fink, J. C. Fuggle, P. J. Duhram, and W. M. Temmerman, Phys. Rev. B 37, 5158 (1988).CrossRefADSGoogle Scholar
  5. [4]
    M. Suzuki, Phys. Rev. B 39, 2312 (1989).CrossRefADSGoogle Scholar
  6. [5]
    H. Yonezawa, Y. Hidaka, M. Suzuki, and T. Shigematsu, in Proceedings of the Materials Research Society Spring Meeting, San Diego, California, 1989 (to be published).Google Scholar
  7. [6]
    J. M. Tarascon, L. H. Greene, W. R. McKinnon, G. W. Hull, and T. H. Geballe, Nature (London) 235, 1373 (1987).Google Scholar
  8. [7]
    S. Uchida, Physica B 148, 185 (1987).CrossRefGoogle Scholar
  9. [8]
    S. Tajima, T. Nakahashi, S. Uchida, and S. Tanaka, Physica C 156, 90 (1988)CrossRefADSGoogle Scholar
  10. S. Tajima, S. Uchida, S. Tanaka, S. Kanbe, K. Kitazawa, and K. Fueki, Jpn. J. Appl. Phys. 26, L432 (1987).CrossRefADSGoogle Scholar
  11. [9]
    J. Orenstein, G. A. Thomas, D. H. Rapkine, C. G. Bethea, B. F. Levine, R. J. Cava, E. A. Rietman, and D. W. Johnson, Jr., Phys. Rev. B 36, 729 (1987).CrossRefADSGoogle Scholar
  12. [10]
    S. L. Herr, K. Kamarâs, C. D. Porter, M. G. Doss, D. B. Tanner, D. A. Bonn, J. E. Greedan, C. V. Stager, and T. Timusk, Phys. Rev. B 36, 733 (1987).CrossRefADSGoogle Scholar
  13. [11]
    S. Etemad, D. E. Aspnes, P. Barboux, G. W. Hull, M. K. Kelly, J. M. Tarascon, R. Thompson, S. L. Herr, K. Kamarâs, C. D. Porter, and D. B. Tanner, Proc. Materials Research Society, Boston, 1987.Google Scholar
  14. [12]
    M. Suzuki, Y. Enomoto, T. Murakami, and T. Inamura, J. Appl. Phys. 53, 1622 (1982).CrossRefADSGoogle Scholar
  15. [13]
    J. M. Ginder, M. G. Roe, Y. Song, R. P. McCall, J. R. Gaines, and E. Ehrenfreunt, Phys. Rev. B 37, 7506 (1988), The author is much obliged to H. Katayama-Yoshida for his pointing out the important relationship between this reference and the present experiment.Google Scholar
  16. [14]
    S. Tajima, S. Uchida, A. Masaki, H. Takagi, K. Kitazawa, S. Tanaka, and A. Katsui, Phys. Rev. B 32, 6302 (1985).CrossRefADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin, Heidelberg 1989

Authors and Affiliations

  • M. Suzuki
    • 1
  1. 1.NTT Opto-Electronics Laboratories162 Tokai, Ibaraki 319-11Japan

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