Comparative high-field magnetotransport of the oxypnictide superconductors RFeAsO1-xFx (R=La, Nd) and SmFeAsO1-δ

We compare magnetotransport of the three iron-arsenide-based compounds ReFeAsO (Re=La, Sm, Nd) in very high DC and pulsed magnetic fields up to 45 and 54 T, respectively. Each sample studied exhibits a superconducting transition temperature near the maximum reported to date for that particular compound. While high magnetic fields do not suppress the superconducting state appreciably, the resistivity, Hall coefficient. and critical magnetic fields, taken together, suggest that the phenomenology and superconducting parameters of the oxypnictide superconductors bridges the gap between MgB2 and YBCO.