Results from a systematic Fresnel contrast (in-line electron holography) study of a large number of grain boundary potentials from undoped, donor-doped and acceptor-doped polycrystalline strontium titanate samples were summarized. An assessment was made of whether the measured variations in potential could be used to provide information about space charge distributions at the boundaries, or whether they were instead dominated by local changes in composition, density and specimen thickness. The effects on the measured contrast of both specimen preparation for transmission electron microscopy and irradiation by the high-energy electron beam were also considered.

The Measurement and Interpretation of Electrostatic Potential Profiles across Grain Boundaries in Strontium Titanate. S.J.P.Longworth, K.M.Knowles, R.E.Dunin-Borkowski: Journal of Physics - Conference Series, 2006, 26, 235-8