Microsc. Microanal. Microstruct. 8, 89-102 (1997)
DOI: 10.1051/mmm:1997108

HREM Image Analysis by Fourier Filtering of Reflections with Long Extinction Distances: Application to the Spinel/MgO System

Reinald Hillebrand, Peter Werner, Heino Sieber et Dietrich Hesse

Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle/Saale, Germany

Abstract
It is known that high resolution electron microscopy can provide quantitative information on the nature of crystalline materials. In the present paper an image processing technique is introduced that profits from long extinction distances in electron diffraction. It is applied to study the real structure of spinel films, which were grown on MgO substrates by solid state reactions. The simulation of electron diffraction and the analysis of calculated contrast tableaus revealed that the intensity of the spinel-specific reflections is a monotonous function of the crystal thickness in a wide range of parameters. Making use of this relation experimental micrographs of spinel films and MgO/spinel interfaces are interpreted by Fourier filtering. First, it is the aim of the technique developed to map the local thickness of spinel films by evaluating the related contrast. Second, if the specimens are sufficiently plane, the degree of abruptness of the different spinel/MgO reaction fronts can be analysed.

PACS
0780 - Electron and ion microscopes and techniques.
6116D - Electron microscopy determinations of structures.

Key words
electron microscopy -- Fourier analysis -- image processing -- HREM image analysis -- Fourier filtering of reflections -- long extinction distances -- spinel MgO system -- high resolution electron microscopy -- spinel films


© EDP Sciences 1997