Scanning Microscopy


Cathodoluminescence (CL) in the Scanning Electron Microscope (SEM) was performed for both ceramic pellets and thin films of YBaCuO high TC superconductors. Image processing provided additional quantitative information. For single phase films, we demonstrated the possibility to create thickness maps in real time from the CL pictures. The gradual thickness variation within the sample was revealed by the histogram of the thickness image. The continuity of the film was observed at a few threshold thicknesses values, defined by the fraction of the occupied area. At the conduction threshold value, the location and width of the conducting paths could be estimated. The analysis was of a lateral resolution better than 1 μm and of a submicron thickness resolution. Insulating impurity grains embedded in the YBaCuO ceramic pellet, which could not be recognized by secondary electrons, were revealed by the CL mode in the SEM. Their long luminescence lifetime was recorded at different time scales and provided an estimation of the lifetime and density of generated carriers. This analysis can be applied to any other high TC superconductors.

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