Critical current density and vortex dynamics in uranium irradiated Co-doped BaFe2As2

Abstract

We report the effect of defects introduced by heavy-ion irradiation with 2.6GeV uranium ions at several matching fields in single crystalline Ba(Fe0.925Co0.075)2As2. The suppression rate of Tc at lower matching fields is larger than that at higher matching fields. The critical current density calculated from magnetic hysteresis loop is enhanced up to 4.1×106A/cm2 at 2K. Clear dips in magnetic hysteresis loops near zero field are observed at high matching fields. Field dependence of normalized relaxation rate is suppressed, and the relationship between the dip and the relaxation rate is discussed.