Reconstruction of Thickness and Composition of Stratified Materials by Means of 3D Micro X-ray Fluorescence Spectroscopy

Abstract

The recently developed 3D micro X-ray fluorescence spectroscopy (3D Micro-XRF) enables three-dimensional resolved, nondestructive investigation of elemental distribution in samples in the micrometer regime. Establishing a reliable quantification procedure is the precondition to render this spectroscopic method into a true analytical tool. One prominent field of application is the investigation of stratified material. A procedure for the quantitative reconstruction of the composition of stratified material by means of 3D Micro-XRF is proposed and validated. With the procedure, it is now possible to determine nondestructively the chemical composition and the thickness of layers. As no adequate stratified reference samples were available for validation, stratified reference material has been developed that is appropriate for 3D Micro-XRF or other depth-sensitive X-ray techniques.

Combined 1D, 2D and 3D micro-XRF techniques for the analysis of illuminated manuscripts

“…With fundamental parameter algorithms based on the Sherman equation, 8 uorescence information can be converted into mass depositions and in the case of confocal measurements, the elemental compositions and thicknesses of layers can be derived. 9,10 One micro-XRF spectrum contains information about elements on one specic lateral spot without any depth resolution. The information depth for each element in a specic matrix is dependent on the uorescence energy and, thus, element and uorescence line specic.…”

Quantitative X-ray fluorescence analysis of samples of less than ‘infinite thickness’: Difficulties and possibilities

“…Malzer and Kanngieβer [75] proposed an algorithm for the primary fluorescence radiation intensity in 3D-µ-XRF measurements. The proposed algorithm allows determining nondestructively the chemical composition and the thickness of layers of stratified material [76]. Developed FP equations make it possible to calibrate 3D-µ-XRF spectrometer with thick multi-element standard reference materials.…”

Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

“…This is achieved by moving the region of interest of a sample into the confocal excitation/detection volume using a set of lateral XY stages and a vertical Z stage. The confocal geometry creates a spatially constricted ellipsoidal [11] or spherical [12] X-ray excitation/detection volume, which allows for the nondestructive elemental analysis of surface and subsurface regions of interest, such as stratified layers [8], paint layers [13], embedded metal-doped polymer layers [14,15], and lithium-ion battery cathodes. [16] However, one drawback of confocal MXRF is the time required to obtain full 3D elemental maps, which can vary from days to weeks, depending on the energy of the Xray source, sample composition, sample size, desired horizontal and vertical resolutions, and dwell time needed to obtain an appropriate signal-to-noise ratio.…”