Electron energy-loss spectroscopic profiling of thin film structures: 0.39 nm line resolution and 0.04 eV precision measurement of near-edge structure shifts at interfaces

The method of energy-loss spectroscopic profiling of interfaces, planar defects and thin film structures in a transmission electron microscope with an imaging filter is introduced. Ways to calculate true chemical profiles with near-atomic line resolution are described. An application to the perovskite system (La,Ca)MnO3/SrTiO3 demonstrates that the technical merit of this method is the simultaneous achievement of high resolution (down to 0.39 nm line resolution), high chemical sensitivity (around 1 at% standard deviation) and very high precision in the measurement of shifts of edge onsets and energy-loss near-edge structure details (down to 0.04 eV). The combination of these characteristics makes the method a powerful tool for the quantification of diffusion and segregation of elements on the atomic scale in a variety of materials systems.