Observation of the spatial distribution of the critical current density in TlBaCaCuO thin film

With Low Temperature Scanning Electron Microscopy, the spatial distribution of the critical current density has been imaged in TlBaCaCuO thin films fabricated by DC magnetron sputtering on zirconia substrate. The experimental results show that the local maximum critical current density of the film is about three times greater than the local minimum critical current density, which indicates a strong homogeneity of the critical current density distribution. The microstructure analysis implies that the inhomogeneous critical current density distribution is due to the granular structures and the existence of several structure phases