Abstract
Optical data over a broad energy range (∼ 0.01 eV to ∼ 6 eV) for a series of La2−xSrxCuO4-δ compounds are obtained in parallel with the Meissner effect and the superconductivity transition temperature, Tc. Two noteworthy trends in the optical spectra are observed as the Sr concentration is increased in small steps from x = 0 to x = 0.3. First is the appearance of a low frequency band in the reflectivity, R, whose strength follows closely the Meissner effect and Tc measured on the same set of samples. The position of the onset of this band is pinned at ∼0.9 eV for all values of x. The origin of this band in R is identified as an absorption process due to an electronic transition with a large oscillator strength. Second is the appearance and disappearance of an intense vibrational mode whose strength also tracks “superconductivity”. This sharp structure in the far infrared is a characteristic vibrational mode associated with the dopant induced electronic state.
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S. Etemad, D.E. Aspnes, M.K. Kelly, R. Thompson, J.-M. Tarascon, and G.W. Hull, to be published. Highlights of this work can be found in the Proceedings of the International Conference on High Temperature Superconductivity, Trieste (Italy) June 1987; Edited by Yu Lu and S. Lundquist, World Scientific Publishers (Singapore), in press.
S. Tajima, S. Uchida, S. Tanaka S. Kanbe, K. Kitazawa and K. Fueki, Japonese J. Appl. Phys.26 (1987).
K. Kamaras, C.D. Porter, M.G. Doss, S.L. Herr, D.B. Tanner, D.A. Bonn, J.E. Greedan, A.H. O’Reilly, C.V. Stager, and T. Timusk, Phys. Rev. Lett. 59, 919 (1987).
S. L. Herr, K. Kamaras, C.D. Porter, D.B. Tanner, S. Etemad, D.E. Aspnes, M.K. Kelly, and J.M. Tarascon to be published.
In extending the measurements to FIR region we find that the absolute scale for R in Figure 1 that is set by the ellipsometry measurements is too high. σ(ω) are obtained by extrapolating the zero frequency value of R at low temperatures to unity.
S.L. Herr, K. Kamaras, C.D. Porter, M.G. Doss, D.B. Tanner, D.A. Bonn, J.E. Greedan, C.V. Stager and T. Timusk, Phys. Rev. B36, 733(1987).
P.E. Sulewski, T.W. Noh, J.T. MaWhirter, and A.J. Sievers, Phys. Rev. B36, 5735(1987).
G.A. Thomas, A.J. Millis, R.N. Bhatt, R.J. Cava, E.A. Reitman, Phys. Rev. B35, (1987).
M.J. Rice Phys. Rev. Lett. 37, 36(1976); and M.J. Rice Solid State Commun. 31, 93(1979).
As an example see S. Etemad, Phys. Rev. 24, 4959(1987) for study of Peierls distortion in TTF-TCNQ.
F.E. Pinkerton, B.C. Webb, A.J. Sievers, J.W. Wilkins, amd L.J. Sham, Phys. Rev. B30, 3068(1984).
T. Koida, H. Fukutani, A. Fujimori, R. Suzuki, T. Shidara, T. Takahashi, S. Hosoya, and M. Sato (preprint).
The optical study at University of Tokyo communicated by S. Tanaka in the Proceedings of the International Conference on High Temperature Superconductivity, Trieste (Italy). June 1987; Edited by Yu Lu and S. Lundquist, World Scientific Publishers (Singapore), in press.
Z. Schlesinger, R.T. Collins, D.L. Kaiser and F. Hotzberg, Phys. Rev. Lett. 59, 1958(1987).
J. Orenstein and D.H. Rapkine, comment on Reference 3.
We note that all of the single crystal and oriented film reflection results cannot be fitted satisfactorily to a Drude expression.
J.M. Tarascon, L.H. Greene, P. Barboux, W.R. McKinnon, G.W. Hull, T.P. Orlando, K.A. Delin, S. Foner and E. J. McNiff.Jr., Phys. Rev. B December 1987.
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Etemad, S., Aspnes, D.E., Barboux, P. et al. Optical Properties of Dopant Induced States in La2−xSrxCuO4-δ Compounds. MRS Online Proceedings Library 99, 135–140 (1987). https://doi.org/10.1557/PROC-99-135
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DOI: https://doi.org/10.1557/PROC-99-135