Field-dependent anomalies in the thermodynamic and transport properties of RuSr2GdCu2O8-Evidence for a spin-flop transition

► Single crystal films of RuSr2GdCu2O8 (Ru:1212) were prepared and their hole content measured. ► Thin film magnetizable and polycrystalline TEP data give evidence for a spin-flop transition. ► The ruthenium ions interact ferromagnetically above their magnetic ordering temperature. ► The superconducting transition temperature Tc is increased from 38 to 42 K by fields of a few Tesla. ► Our observations are consistent with a spontaneous vortex state below Tc in zero applied field.