Determination of the complex dielectric function of epitaxial SrTiO3 films using transmission electron energy-loss spectroscopy

A study demonstrated that electron energy-loss spectroscopy in transmission electron microscopy is a useful technique for analysis of the high-frequency dielectric properties on a microstructural level. Changes in the low frequency dielectric function between Sr deficient and stoichiometric films were much larger compared to the changes in the high-frequency function. It was found that strain and compositional deviations from the bulk value resulted in decreased ability to withstand dielectric breakdown.