High-precision mapping of fluorine and lithium in energy materials by means of laser-induced XUV spectroscopy (LIXS)

Di Qu,Natacha Ohannessian,Corino Wyder,Matthias Trottmann,Adrian Wichser,Thomas Lippert,Davide Bleiner

doi:10.1016/j.sab.2021.106214

Abstract

Laser-induced breakdown spectroscopy (LIBS) is a well-established elemental analysis method, thanks to negligible sample preparation, rapid analysis, and a spatially resolved sensitivity down to trace level, in any kind of matrix. State-of-the-art LIBS is operated in the optical spectral range (UV-VIS). Unfortunately, the measurement precision is limited by the moderate stability and repeatability of the plasma emission. The detection and sensitivity to crucial elements such as light elements and halogens are also limited. This is particularly critical for inhomogeneous materials where signal fluctuation is related to the spatial elemental distribution. To overcome these disadvantages specific, LIBS techniques arrangement are often required. Laser-induced XUV Spectroscopy (LIXS) has some intrinsic advantages for overcoming some of the above mentioned limitations and it can support the spectroscopic information collected in the UV-VIS range.

Highlights

Laser-induced breakdown spectroscopy (LIBS) is a well-established elemental analysis method
The spectra in the XUV (5–20 nm) and UV-VIS (193–603 nm) ranges from laser-induced plasma emission were acquired simultaneously without temporal evolution under low pressure. These exper imental conditions are not optimized for elemental analysis, the ob tained spectra can be used for a direct comparison of the main characteristics of the laser induced plasma spectrum in the two inves tigated spectral ranges
In the UV-VIS range (Fig. 2.b), the strong transitions are generated from the neutral Li and singly ionized F atom, such as the strongest Li I line at 460.3 nm and the strongest fluorine line F II at 424.6 nm

Summary

Introduction

Laser-induced breakdown spectroscopy (LIBS) is a well-established elemental analysis method. The conventional LIBS is operated in the optical spectral range (UV-VIS) and allows a rapid simultaneously detection of most of elements in a solid sample [1,2,3,4]. In the last de cades several efforts have been made to improve the precision of the technique and generally RSD ranges in a wide interval from 5% to 30% depending on several parameters such as experimental conditions (background environment, pressure etc.), chemical and physical char acteristics of the sample (morphology, composition, homogeneity etc.), duration of the laser pulse, focusing conditions, spectral features of the analyzed elements, detection parameters (gate width and delay time, number of accumulations). An interesting hyphenated approach to enhance the signal and LIBS's sensitivity and stability, was introduced, where the LIBS was coupled with Raman spectroscopy [13,14]

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Results

Conclusion