X-ray fluorescence holography with atomic resolution is a promising tool for imaging of local atomic structures in materials without translational periodicity (e.g. small clusters of atoms or moleculas). However, this holographic method suffers from serious drawbacks (low signal-to-noise ratio in measured holograms, virtual atoms and strong artefacts in reconstructed images). In order to overcome these drawbacks, we proposed two different concepts of x-ray holography with atomic resolution:
X-ray absorption holography [1] increases the holographic signal by measuring the absorption in the sample instead of the fluorescence.
X-ray diffuse scattering holography [2, 3] uses the anomalous diffuse scattering of x rays in the vicinity of the absorption edge of a selected element. This method improves the holographic signal and, in principle, virtual images can be suppressed by measuring holograms at different photon energies. X-ray diffuse scattering holography was applied to the study of Mn impurities in thin GaMnAs layers [4,5].
References:
[1] M. Kopecký, A. Lausi, E. Busetto, J. Kub, A. Savoia: X-ray diffuse scattering holography, Phys. Rev. Lett.
88, 185503 (2002).
[2] M. Kopecký: X-ray diffuse scattering holography. J. Appl. Crystallogr.
37, 711 (2004).
[3] M. Kopecký, J. Fábry, J. Kub, E. Busetto, and A. Lausi: X-ray diffuse scattering holography of a centrosymmetric sample. Appl. Phys. Lett.
87, 231914 (2005).
[4] M. Kopecký M., J. Kub, E. Busetto, A. Lausi, M. Cukr, V. Novák, K. Olejník, J. P. Wright, J. Fábry: Location of Mn sites in ferromagnetic Ga
1-xMn
xAs studied by means of x-ray diffuse scattering holography. J. Appl. Cryst.
39, 735 (2006).
[5] M. Kopecký, E. Busetto, A. Lausi, Z. Šourek, J. Kub, M. Cukr, V. Novák, K. Olejník, J. P. Wright: Imaging of interstitial atoms in Ga
1-xMn
xAs layer by means of x-ray diffuse scattering, J. Appl.. Cryst.
41, 544 (2008).
