One-dimensional pinning behavior in Co-doped BaFe_2As_2 thin films

摘要

Angle-resolved transport measurements revealed that planar defects dominate flux pinning in the investigated Co-doped BaFe_2As_2 thin film. For any given field and temperature, the critical current depends only on the angle between the crystallographic c-axis and the applied magnetic field but not on the angle between the current and the field. The critical current is therefore limited only by the in-plane component of the Lorentz force but independent of the out-of-plane component, which is entirely balanced by the pinning force exerted by the planar defects. This one-dimensional pinning behavior shows similarities and differences to intrinsic pinning in layered superconductors.