Upper critical fields well above 100 T for the superconductor SmFeAsO0.85F0.15 with T-c=46 K
We report specific-heat measurements at magnetic fields up to 20 T on the recently discovered superconductor SmFeAsO0.85F0.15. The B-T diagram of a polycrystalline SmFeAsO0.85F0.15 sample with T-c=46 K was investigated. The temperature dependence of B-c2 was extracted from the specific-heat curves; the corresponding B-c2(T=0) value derived from the Werthamer-Helfand-Hohenberg formula being 150 T. Based on magnetization measurements up to 9 T, a first estimation of the field dependence of the inductive critical current J(c) is given. Evidence for granularity is found. The presence of a peak effect is reported, suggesting a crossover in the vortex dynamics, in analogy to the behavior observed in high T-c cuprates.