X-ray fluorescence holography

Abstract

X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy.

Atomic Image Reconstruction from Atomic Resolution Holography Using <i>L</i>₁-Regularized Linear Regression

“…Local atomic structures have been intensively studied recently by inverse x-ray fluorescence holography (IXFH) [1][2][3][4] using synchrotron radiation facilities such as SPring-8. The method can measure the three-dimensional (3D) local atomic structure around dopants in crystals [5] and atomic position fluctuations [6,7].…”

In-Plane Positional Fluctuations of Zinc Atoms in Single Crystal Mg₈₅Zn₆Y₉ Alloy Studied by X-ray Fluorescence Holography

“…X-ray uorescence holography (XFH) 19) can visualize the three-dimensional atomic con gurations around the selected elements and provides useful information on the local arrangements of the substitutional Zn and Y atoms in the LPSO phase. In particular, XFH is highly sensitive to positional uctuations of atoms 19) .…”

“…In particular, XFH is highly sensitive to positional uctuations of atoms 19) . Thus we can directly obtain real-space information on the positional uctuations of the substitutional atoms.…”

X-ray fluorescence holography studies for a Cu3Au crystal

“…This results in a modulation or holographic oscillations of the fluorescence yield emitted from absorbing atoms as the sample is rotated relative to the direction of the incident beam. Since the holographic term is small, XFH usually requires intense synchrotron beams for obtaining high signal-to-noise ratio [5]. Synchrotron radiation is also required for performing multi-energy experiments which enable to eliminate holographic twin-images [6,7].…”