We have investigated spatial distribution of local critical current density (Jc) in a Co-doped BaFe2As2 (Ba122:Co) film based on scanning Hall-probe microscopy (SHPM). In-plane Jc distribution was derived from the magnetic field distribution. Thanks to the high-resolution characterization, local obstacle can be detected clearly, as well as a local spot with extremely high Jc over 7 MA/cm2, which is among the highest value at remanent state reported for this series of films so far. The SHPM allows us to separate the influence of current blocking obstacles and intrinsic flux pinning properties on Jc. Validity of the Jc analysis was checked by a magnetization measurement based on a SQUID magnetometer. Moreover, we investigated the Jc distributions at different temperatures by SHPM and studied their probability distribution functions (PDFs). PDFs are found to be scaled by a Weibull function with the same shape parameter, while Jcs are decreasing with higher temperature. These results indicate that the intrinsic in-plane pinning is controlled by the same mechanism.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering