High-resolution EELS on high entropy perovskite oxide thin films

The properties of perovskites are defined by the elements on the A- and B-site. They can be influenced via the high-entropy concept by substituting the A- or B-site with five or more different elements in equiatomic ratio. Many high-entropy perovskites have been synthesized as bulk but only a few of them have been grown as thin films, where the properties can differ. (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ is a manganese based high-entropy perovskite with an orthorhombic structure, which has been synthesized as powder but not as thin film. We have grown thin films of the high-entropy perovskite oxide (La_0.2Nd_0.2Gd_0.2Sm_0.2Y_0.2)MnO₃ on SrTiO₃(001) substrates by pulsed laser deposition. By high-resolution dark field scanning transmission electron microscopy (DF-STEM), the structure was confirmed. Furthermore, the high-entropy character of the A-site with an ordered manganese lattice on the B-site was visualized by electron energy loss spectroscopy (EELS) on atomic scale on samples with 7-8 nm thickness prepared by focused ion beam technique (FIB). Different experimental approaches with conventional EELS spectrometers, as well as rapid, direct-electron counting systems are discussed and compared regarding their capabilities. Results from a single scan, as well as dose-fractionated acquisition of multiple frames to minimize beam damage to the sample, with challenging drift correction of the periodic lattice, are presented.

This webinar, in conjunction with the Center for Electron Microscopy and Analysis (CEMAS) at The Ohio State University, will focus on examples of how advances in energy dispersive spectroscopy (EDS) and electron backscatter diffraction (EBSD) can help improve your analysis. The webinar will be broken down into two talks: 1) High-precision EBSD from spherical harmonic indexing and 2) Few compelling examples of the impact of EDS on alloy design.