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

• Published in: Chemistry of materials 2002-01, Vol.14 (1), p.135-143
• Main Authors: Rom, I, Hofer, F, Bucher, E, Sitte, W, Gatterer, K, Fritzer, H. P, Popitsch, A
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm011108w

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.