Superconducting fluctuations and anomalous phonon renormalization much above superconducting transition temperature in Ca4Al2O5.7Fe2As2
Data(s) |
01/05/2012
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Resumo |
Raman studies on Ca4Al2O5.7Fe2As2 superconductor in the temperature range of 5K to 300 K, covering the superconducting transition temperature T-c = 28.3 K, reveal that the Raman mode at similar to 230 cm(-1) shows a sharp jump in frequency by similar to 2% and linewidth increases by similar to 175% at T-o similar to 60 K. Below T-o, anomalous softening of the mode frequency and a large decrease by similar to 10 cm(-1) in the linewidth are observed. These precursor effects at T-0 (similar to 2T(c)) are attributed to significant superconducting fluctuations, possibly enhanced due to reduced dimensionality arising from weak coupling between the well separated (similar to 15 angstrom) Fe-As layers in the unit cell. A large blue-shift of the mode frequency between 300 K and 60 K (similar to 7%) indicates strong spin-phonon coupling in this superconductor. (C) 2012 American Institute of Physics. http://dx.doi.org/10.1063/1.4724206] |
Formato |
application/pdf |
Identificador |
http://eprints.iisc.ernet.in/44769/1/app_phy_let_100_22-2012.pdf Kumar, Pradeep and Bera, A and Muthu, DVS and Shirage, PM and Iyo, A and Sood, AK (2012) Superconducting fluctuations and anomalous phonon renormalization much above superconducting transition temperature in Ca4Al2O5.7Fe2As2. In: APPLIED PHYSICS LETTERS, 100 (22). |
Publicador |
AMER INST PHYSICS |
Relação |
http://dx.doi.org/10.1063/1.4724206 http://eprints.iisc.ernet.in/44769/ |
Palavras-Chave | #Physics |
Tipo |
Journal Article PeerReviewed |