DIRECT IMAGING OF SPATIALLY VARYING POTENTIAL AND CHARGE ACROSS INTERNAL INTERFACES IN SOLIDS

Transmission electron holography is utilized to study the electrostati c potential and associated space charge across grain boundaries in SrT iO3. While pristine boundaries show only the effect of a reduction in density of atoms, doped boundaries indicate the presence of potential barriers and associated space charge due to accumulation of charged po int defects. This Letter demonstrates the viability of electron hologr aphy as a bulk sensitive tool to directly image and quantify the magni tude, sign, and spatial. extent of electrical potential and charge acr oss internal interfaces in solids.