A TEM fresnel diffraction-based method for characterizing thin grain-boundary and interfacial films

Development of microstructure during creep of polycrystalline mullite and a nanocomposite mullite/5vol.% SiC

“…[21][22][23][24][25] The defocus Fresnel technique was used in estimating the thickness of the amorphous grain boundary film in around 20 randomly chosen grain boundaries in the as-sintered materials and in the mullite and nanocomposite specimens crept at 1400 • C under a stress of 48.6 and 50.0 MPa, respectively. The grain boundaries were oriented in the edge-on position by looking at the reflection symmetry of the fringe intensity across the boundary.…”

Projected potential profiles across interfaces obtained by reconstructing the exit face wave function from through focal series

“…Apart from off-axis holography, in which the phase of the transmitted wave function is measured by reconstructing its interference with a reference wave [1], microscope aberrations, such as defocus and spherical aberration may also be used to encode local variations in the phase of the exit face wave function in the image intensity. Stobbs and coworkers [5][6][7] developed an approach to use Fresnel contrast (contrast in largely defocused images of objects containing local phase differences) to analyze potential profiles across interfaces by fitting a few parameter model of the mean inner potential profile to the fringe contrast. This approach was reviewed and extended further by Dunin-Borkoski [8].…”

Interface analysis using elastic scattering in the transmission electron microscope: Application to the oxidation of silicon

“…2) but the information about composition changes has been largely ignored until r e~e n t l y .~.~ The method described here follows the work of Ness et al 4 and results are obtained by matching the observed fringe profiles with theoretical ones simulated using a computer model of a proposed structure of the thin layer.…”