Raman spectral temperature dependence of Bi{sub 2}Sr{sub 2}Ca{sub 1{minus}x}(Y{sub x})Cu{sub 2}O{sub 8} (x=0 and 1)
- Inst. des Materiaux, Nantes (France). Lab. de Physique Cristalline
- Ecole Polytechnique Federale, Lausanne (Switzerland). Inst. de Physique Appliquee
The authors have investigated the temperature dependence of phonon and magnon Raman scattering of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (2212) and Bi{sub 2}Sr{sub 2}YCu{sub 2}O{sub 8} single crystals. They found no significant frequency shifts above and below {Tc} nor magnons in the yttrium free 2212 compound. The main 460 cm{sup {minus}1} O-Sr phonon is not coupled to an electronic continuum whereas it appears clearly that the 630 cm{sup {minus}1} O-Bi phonon does couple owing to its Fano shape. Issue whether the oxygen-CuO{sub 2} 290 cm{sup {minus}1} phonon couples or not remains open. On the contrary, some phonons of the Raman spectra of yttrium 2212 crystals show changes around T{sup *} = 125 K in frequency, linewidth and intensity. For instance, anomalous temperature dependence is evidenced for the frequency and linewidth of the O-Bi lines (628, 670 cm{sup {minus}1}) and CuO{sub 2} lines (310, 358 cm{sup {minus}1}), and the linewidth of the mode at 500 cm{sup {minus}1}. A strong and large feature (3060 cm{sup {minus}1}) stemming possibly from two-magnon scattering has also been recorded at 8 K and 300 K. The exchange integral J is estimated to be {minus}140 meV.
- OSTI ID:
- 538209
- Report Number(s):
- CONF-960163-; ISBN 0-8194-2070-0; TRN: 97:018592
- Resource Relation:
- Conference: Photonics West `96: conference on quantum well and superlattice physics VI, San Jose, CA (United States), 27 Jan - 2 Feb 1996; Other Information: PBD: 1996; Related Information: Is Part Of Spectroscopic studies of superconductors. Part A: Infrared and Raman spectra; Bozovic, I.; Marel, D. van der [eds.]; PB: 337 p.; Proceedings/SPIE, Volume 2696
- Country of Publication:
- United States
- Language:
- English
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