Visualization of Compositional Fluctuations in Complex Oxides Using Energy-Filtering Transmission Electron Microscopy

Abstract

Energy-filtering transmission electron microscopy (EFTEM) was used to evaluate the purity and phase composition of perovskite- and spinel-type oxides, using La1 - x Sr x CoO3 - δ (x = 0.5, 0.6) and CdCr2 - x In x O4 (x = 0.05, 0.5) prepared via a mixed oxide route, the glycine nitrate process and a wet chemical method, respectively. Energy-filtered images of the elements of interest were acquired to obtain the two-dimensional elemental distributions within polycrystalline samples at high lateral resolution. The presence of other crystalline phases in addition to the expected perovskite and spinel phases is easily recognized in the elemental distribution images. Additionally, those secondary phases were identified using spectroscopical techniques available in the transmission electron microscope, namely, energy-dispersive X-ray spectrometry (EDXS) and electron energy loss spectroscopy (EELS). The present investigation demonstrates that energy-filtering transmission electron microscopy is a powerful technique for assessing homogeneity of materials with nanometer resolution and high-detection sensitivity.

Nanoimaging and Spectroscopic Analysis of Rubber/ZnO Interfaces by Energy-Filtering Transmission Electron Microscopy

“…[1][2][3][4][5] EFTEM is a powerful tool for investigating material nanostructures. [6][7][8] It allows us to create elemental distribution images by electron spectroscopic imaging (ESI) and to perform a quantitative chemical analysis by electron energy loss spectroscopy (EELS). 9 For materials with high resistivity against electron beams such as metals or semiconductors, elemental analysis with a spatial resolution of less than 1 nm has been achieved.…”

“…We have been employing EFTEM for the characterization of nanostructures in polymers and composites. − EFTEM is a powerful tool for investigating material nanostructures. − It allows us to create elemental distribution images by electron spectroscopic imaging (ESI) and to perform a quantitative chemical analysis by electron energy loss spectroscopy (EELS) , EFTEM has also been employed for the characterization of polymer/polymer interfaces. ,,, However, the instability of polymer specimens against electron beams limits high-resolution nanoanalysis by EFTEM.…”

The stoichiometry of single nanoparticles of copper zinc tin selenide

“…12 Due to its excellent spatial resolution which is in the nanometre range, this method allows the detailed chemical analysis of nanostructured materials and even individual nanoparticles. 13 Cu 2 ZnSnSe 4 nanoparticles have been prepared by the oleylamine route 14 with a slightly modified synthesis protocol using copper(I) acetate, zinc(II) iodide, tin(IV) acetate and elemental Se as starting materials (see ESIw for details). A bright field TEM image of the obtained particles is presented in Fig.…”

Analytical Electron Microscopy in Materials and Biological Sciences

“…The most obvious advantage of EFTEM imaging is the measurement of compositional information in the form of elemental maps which can easily be quantified in order to yield concentration and chemical phase maps [9,10]. The elemental mapping approach can be the best way to analyse nano-scale features in materials such as fine precipitates and interfaces/boundaries, since two dimensional fluctuation in composition around such small features, which may be easily missed by point or line-scale analyses, can be revealed in images of elemental distributions [11]. EFTEM allows to record elemental maps at sub-nanometre resolution, being mainly limited by chromatic and spherical aberration of the objective lens and by delocalisation of the inelastic scattering process [12,13,14].…”