Abstract
We have used a scanning tunneling microscope in potentiometry mode to investigate the local electric potential distribution in current carrying epitaxial thin films, with magnetotransport properties similar to the ones of single crystals. Scans imaging simultaneously the surface topography and the potential distribution have been obtained with an unprecedented resolution. In textured sharp potential steps coincide with some of the grain boundaries, whereas other grains are electrically well connected. The precise nature of the local electronic transport, the percolation of the current through the grain network, and the existence of phase separated insulating domains are then discussed.
- Received 11 February 2000
DOI:https://doi.org/10.1103/PhysRevB.62.8596
©2000 American Physical Society