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Interferometric Diffraction from Amorphous Double Films

Published online by Cambridge University Press:  02 October 2015

Aram Rezikyan ,
James A. Belcourt  and
Michael M. J. Treacy
Aram Rezikyan*
Affiliation:
Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
James A. Belcourt
Affiliation:
Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
Michael M. J. Treacy
Affiliation:
Department of Physics, Arizona State University, Tempe, Arizona 85287, USA
*
*Corresponding author. [email protected]
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Abstract

We explore the interference fringes that arise in diffraction patterns from double-layer amorphous samples where there is a substantial separation, up to about a micron, between two overlapping thin films. This interferometric diffraction geometry, where both waves have interacted with the specimen, reveals phase gradients within microdiffraction patterns. The rapid fading of the observed fringes as the magnitude of the diffraction vector increases confirms that displacement decoherence is strong in high-energy electron scattering from amorphous samples. The fading of fringes with increasing layer separation indicates an effective illumination coherence length of about 225 nm, which is consistent with the value of 270 nm expected for the heated Schottky field emitter source. A small reduction in measured coherence length is expected because of the additional energy spread induced in the beam after it passes through the first layer.

Keywords

interferometric diffractionamorphous double layerinterference fringes
Type
Materials Applications
Information
Microscopy and Microanalysis , Volume 21 , Issue 5 , October 2015 , pp. 1348 - 1360
Copyright
© Microscopy Society of America 2015 

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References

Born, M. & Wolf, E. (1999). Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light. Cambridge, UK: Cambridge University Press.CrossRefGoogle Scholar
Cowley, J. (1992). Twenty forms of electron holography. Ultramicroscopy 41(4), 335–348.Google Scholar
Gibson, J.M. & Treacy, M.M.J. (2008). Beam transit effects in single molecule coherent diffraction. Phys Rev B 78, 245401.Google Scholar
Gibson, J.M., Treacy, M.M.J., Sun, T. & Zaluzec, N.J. (2010). Substantial crystalline topology in amorphous silicon. Phys Rev Lett 105(12), 125504.CrossRefGoogle ScholarPubMed
Gibson, J.M., Treacy, M.M.J. & Voyles, P.M. (2000). Atom pair persistence in disordered materials from fluctuation microscopy. Ultramicroscopy 83, 169–178.Google Scholar
Hirsch, P., Howie, A., Nicholson, R., Pashley, D.W. & Whelan, M.J. (1977). Electron Microscopy of Thin Crystals. Malabar, Florida: Krieger Publishing.Google Scholar
Keblinski, P., Phillpot, S.R., Wolf, D. & Gleiter, H. (1997). Amorphous structure of grain boundaries and grain junctions in nanocrystalline silicon by molecular-dynamics simulation. Acta Mater 45(3), 987–998.Google Scholar
Rezikyan, A., Jibben, Z., Rock, B.A., Zhao, G., Koeck, F.A.M., Nemanich, R.F. & Treacy, M.M.J. (2015). Speckle suppression by decoherence in fluctuation electron microscopy. Microscopy & Microanalysis, 2015 (Accepted on August 11, 2015).Google Scholar
Treacy, M.M.J. & Gibson, J.M. (1996). Variable coherence microscopy: A rich source of structural information from disordered materials. Acta Cryst A 52, 212–220.CrossRefGoogle Scholar
Treacy, M.M.J. & Gibson, J.M. (2012). Examination of a polycrystalline thin-film model to explore the relation between probe size and structural correlation length in fluctuation electron microscopy. Microsc Microanal 18, 241–253.CrossRefGoogle ScholarPubMed
Treacy, M.M.J., Gibson, J.M., Fan, L., Paterson, D.J. & McNulty, I. (2005). Fluctuation microscopy: A probe of medium range order. Rep Prog Phys 68(12), 2899–2944.Google Scholar
Treacy, M.M.J., Kumar, D., Rougée, A., Zhao, G., Buseck, P.R., McNulty, I., Fan, L., Rau, C. & Gibson, J.M. (2007). Probing medium-range structural correlations by fluctuation microscopy. J Phys Condens Matter 19, 455201.CrossRefGoogle Scholar
Wang, Y.C., Chou, T.M., Libera, M. & Kelly, T.F. (1997). Transmission electron holography of silicon nanospheres with surface oxide layers. Appl Phys Lett 70, 1296–1298.Google Scholar
Wanner, M., Bach, D., Gerthsen, D., Werner, R. & Tesche, B. (2006). Electron holography of thin amorphous carbon films: Measurement of the mean inner potential and a thickness-independent phase shift. Ultramicroscopy 106, 341–345.Google Scholar
Williams, D.B. & Carter, C.B. (2009). Transmission Electron Microscopy. Springer Science + Business Media, LLC, New York: Springer.Google Scholar
Wooten, F., Winer, K. & Weaire, D. (1985). Computer-generation of structural models of amorphous Si and Ge. Phys Rev Lett 54, 1392–1395.CrossRefGoogle ScholarPubMed