Scanning Hall-probe microscopy system for two-dimensional imaging of critical current density in RE-123 coated conductors

We have developed a characterization method for two-dimensional imaging of critical current density in coated conductors (CCs) based on scanning Hall-probe microscopy (SHPM). The distributions of the magnetic field around a sample were measured for several different conditions of external magnetic fields, and then were converted to those of the sheet current density which flowed to shield the external magnetic field or to trap the penetrated magnetic field. As a result, it was found that the amplitude of the sheet current density corresponded to that of critical current density almost in all the area of the sample except for the region where current direction changed. This indicates that we could obtain an in-plane distribution of the critical current density with a spatial resolution of around 100 mu m in non-destructive manner by this method. We believe that this measurement will be a multifunctional and comprehensive characterization method for coated conductors. (C) 2011 Elsevier B.V. All rights reserved.