Orbital and spin effects for the upper critical field in As deficient disordered Fe pnictide superconductors

G. Fuchs, S. -L. Drechsler, N. Kozlova +17

We report B_c2 data for LaO_{0.9}F_{0.1}FeAs_{1-delta} in a wide T and field range up to 60 Tesla. The large slope of B_c2 approx ~ -6 Tesla/K near an improved T_c = 28.5 K of the…