Comparative study of electron and laser beam scanning for local electrical characterization of high-T/sub c/ thin films and junctions

The development of spatially resolved methods for an electrical characterization of thin films and junctions is essential for further progress in physics and applications of high-temperature superconductors. Two methods, electron beam and laser beam scanning, are used to get the high-resolution electrical images. In this paper we present the results of the comparison of electron- and laser-induced responses of the same high-T/sub c/ Josephson junctions. Using a laser-beam-induced thermoelectric response at room temperature and its odd-symmetric behavior across the grain boundaries, we were able to visualize the grain boundary faceting in bicrystal high-T/sub c/ Josephson junctions with the resolution of /spl sim/0.1 /spl mu/m.