Upper critical fields and two-band superconductivity in Sr1-xEux(Fe0.89Co0.11)(2)As-2 (x=0.20 and 0.46)
Mun, Eun Deok
Altarawneh, M. M.
Mielke, C. H.
Zapf, V. S.
The upper critical fields H-c2(T) of single crystals of Sr1-xEux(Fe0.89Co0.11)(2)As-2 (x = 0.20 and 0.46) were determined by radio-frequency penetration depth measurements in pulsed magnetic fields. H-c2(T) approaches the Pauli limiting field but shows an upward curvature with an enhancement from the orbital limited field, as inferred from the Werthamer-Helfand-Hohenberg theory. We discuss the temperature dependence of the upper critical fields and the decreasing anisotropy using a two-band BCS model.
This article is published as Hu, Rongwei, Eun Deok Mun, M. M. Altarawneh, C. H. Mielke, V. S. Zapf, S. L. Bud'ko, and P. C. Canfield. "Upper critical fields and two-band superconductivity in Sr 1− x Eu x (Fe 0.89 Co 0.11) 2 As 2 (x= 0.20 and 0.46)." Physical Review B 85, no. 6 (2012): 064511. DOI: 10.1103/PhysRevB.85.064511. Posted with permission.