Ac susceptibility and static magnetization measurements were performed in the nearly optimally doped LaFeAsO0.9F0.1 and CeFeAsO0.92F0.08 superconductors, complementing earlier results on SmFeAsO0.8F0.2 [ Phys. Rev. B 83 174514 (2011)]. The magnetic field-temperature phase diagram of the mixed superconducting state is drawn for the three materials, displaying a sizable reduction of the liquid phase upon increasing Tc in the range of applied fields (H<5 T). This result indicates that SmFeAsO0.8F0.2 is the most interesting compound among the investigated ones in view of possible applications. The field-dependence of the intragrain depinning energy U0 exhibits a common trend for all the samples with a typical crossover field value (2500 Oe ≲Hcr≲5000 Oe) separating regions where single and collective depinning processes are at work.
Prando, G., Carretta, P., De Renzi, R., Sanna, S., Grafe, H.J., Wurmehl, S., et al. (2012). ac susceptibility investigation of vortex dynamics in nearly optimally doped RFeAsO1-xFx superconductors (R = La, Ce, Sm). PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 85, 1-9 [10.1103/PhysRevB.85.144522].
ac susceptibility investigation of vortex dynamics in nearly optimally doped RFeAsO1-xFx superconductors (R = La, Ce, Sm)
SANNA, SAMUELE;
2012
Abstract
Ac susceptibility and static magnetization measurements were performed in the nearly optimally doped LaFeAsO0.9F0.1 and CeFeAsO0.92F0.08 superconductors, complementing earlier results on SmFeAsO0.8F0.2 [ Phys. Rev. B 83 174514 (2011)]. The magnetic field-temperature phase diagram of the mixed superconducting state is drawn for the three materials, displaying a sizable reduction of the liquid phase upon increasing Tc in the range of applied fields (H<5 T). This result indicates that SmFeAsO0.8F0.2 is the most interesting compound among the investigated ones in view of possible applications. The field-dependence of the intragrain depinning energy U0 exhibits a common trend for all the samples with a typical crossover field value (2500 Oe ≲Hcr≲5000 Oe) separating regions where single and collective depinning processes are at work.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.