Direct extraction of quantitative structural information from x-ray fluorescence holograms using spherical-harmonic analysis

Wang, Yuhao; Bai, Jianming; Tyson, Trevor

doi:10.1103/physrevb.85.220102

Cited by 1 publication

(1 citation statement)

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“…The usage of an orthogonal wavelet family [38] should reduce the number of artefacts in the wavelet transform space and allow exact 3D imaging of the local structure. This could be done in harmonic space in analogy with the recent approach demonstrated for XFH [39]. The R-factor analysis could be extended by introducing additional parameters of the structurelike local distortion of the lattice around dopants.…”

Section: Discussionmentioning

confidence: 99%

Wavelet analysis of white beam x-ray fluorescence holograms: determination of lattice sites and imaging of local atomic structure

Dul

Korecki

2012

New J. Phys.

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The prospects of atomic structure imaging with the continuous spherical wavelet transform (CSWT) as applied to white beam x-ray fluorescence holograms (XFH) are discussed. Recording of XFH with a white x-ray beam eliminates holographic twin images and minimizes extinction effects. However, the lack of these parasitic effects is accompanied by a limited radial resolution. In this work, by introducing an approximation of the white x-ray spectrum based on the Gumbel distribution, we propose an improvement both in generation of white beam XFH and in data analysis. Using approximate analytical models and realistic numerical simulations, we give a detailed description of the properties and resolution of local structure projections directly obtained from XFH by using wavelet analysis. It is demonstrated that the CSWT and, in particular, its windowed inversion can be effectively used to enhance and speed up reliability factor (R-factor) analysis of the data, which enables precise fully threedimensional localization of multiple lattice sites of dopants. For this, an exact analytic formula for the inversion is given, enabling its fast calculation in a single step. As an example system, we consider magnetic ions in wurtzite GaN.

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Section: Discussionmentioning

confidence: 99%