Superconducting fluctuations (SFs) in SmFeAsO0.8F0.2 (characterized by superconducting transition temperature Tc52.3 K) are investigated by means of isothermal high-resolution dc magnetization measurements. The diamagnetic response above Tc to magnetic fields up to 1 T is similar to that previously reported for underdoped cuprate superconductors and justified in terms of metastable superconducting islands of nonzero order parameter lacking long-range coherence because of strong phase fluctuations. In the high-field regime (H 1.5 T) scaling arguments predicted on the basis of the Ginzburg-Landau theory for conventional SFs are confirmed, at variance with what is observed in the low-field regime. This fact shows that two different phenomena are simultaneously present in the fluctuating diamagnetism, namely the phase SFs of novel character and the conventional SFs. High magnetic fields (1.5 T HHc2) are found to suppress the former while leaving unaltered the latter.
Superconducting phase fluctuations in SmFeAsO0.8F0.2 from diamagnetism at a low magnetic field above Tc / G. Prando, A. Lascialfari, A. Rigamonti, L. Romanó, S. Sanna, M. Putti, M. Tropeano. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 84:6(2011), pp. 064507.064507.1-064507.064507.6. [10.1103/PhysRevB.84.064507]
Superconducting phase fluctuations in SmFeAsO0.8F0.2 from diamagnetism at a low magnetic field above Tc
A. Lascialfari;
2011
Abstract
Superconducting fluctuations (SFs) in SmFeAsO0.8F0.2 (characterized by superconducting transition temperature Tc52.3 K) are investigated by means of isothermal high-resolution dc magnetization measurements. The diamagnetic response above Tc to magnetic fields up to 1 T is similar to that previously reported for underdoped cuprate superconductors and justified in terms of metastable superconducting islands of nonzero order parameter lacking long-range coherence because of strong phase fluctuations. In the high-field regime (H 1.5 T) scaling arguments predicted on the basis of the Ginzburg-Landau theory for conventional SFs are confirmed, at variance with what is observed in the low-field regime. This fact shows that two different phenomena are simultaneously present in the fluctuating diamagnetism, namely the phase SFs of novel character and the conventional SFs. High magnetic fields (1.5 T HHc2) are found to suppress the former while leaving unaltered the latter.File | Dimensione | Formato | |
---|---|---|---|
146.pdf
accesso riservato
Tipologia:
Publisher's version/PDF
Dimensione
595.07 kB
Formato
Adobe PDF
|
595.07 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.