Temperature dependence of phonon Raman scattering in Y2Ba4Cu7O15−δ

✍ Scribed by M Käll; A.P Litvinchuk; P Berastegui; L.-G Johansson; L Börjesson

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 473 KB
• Volume: 225
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90729-3

✦ Synopsis

The temperature dependence ofA s symmetry phonons in a Y2Ba4CuTO~5_~ (J~0.18, Tc=93 K) superconductor have been investigated between 10 and 300 K by means of Raman scattering. The observed changes in frequency and line-width between Tc and 10 K for the CuO2-and BaO-plane oxygen modes are consistent with the opening of a superconducting gap, 2J, between 340 and 430 cm -I. The magnitudes of these phonon anomalies are similar to what has been reported for the respective modes in YBa2Cu307_~ (J= 0.19). The behaviours of the Ba mode and the chain-oxygen mode below To, i.e. softening and hardening respectively, are approximately the same as those we observe in a YBa2Cu4Os (To = 82 K) sample. Evidence ofphonon frequency anomalies at temperatures above T¢ is discussed in relation to differences in doping-level between YBa2Cu4Os and Y2Ba~CuTOIs_6.