Investigation of the wavelength dependence of laser stratigraphy on Cu and Ni coatings using LIBS compared to a pure thermal ablation model

Abstract

In this study, galvanic coatings of Cu and Ni, typically applied in industrial standard routines, were investigated. Ablation experiments were carried out using the first two harmonic wavelengths of a pulsed Nd:YAG laser and the resulting plasma spectra were analysed using a linear Pearson correlation method. For both wavelengths the absorption/ablation behaviour as well as laser-induced breakdown spectroscopy (LIBS) depth profiles were studied varying laser fluences between 4.3-17.2 J/cm 2 at 532 nm and 2.9-11.7 J/cm 2 at 1064 nm. The LIBS-stratigrams were compared with energydispersive X-ray spectroscopy of cross-sections. The ablation rates were calculated and compared to theoretical values originating from a thermal ablation model. Generally, higher ablation rates were obtained with 532 nm light for both materials. The light-plasma interaction is suggested as possible cause of the lower ablation rates in the infrared regime. Neither clear evidence of the pure thermal ablation, nor correlation with optical properties of investigated materials was obtained.

Approach to using 3D laser-induced breakdown spectroscopy (LIBS) data to explore the interaction of FLiNaK and FLiBe molten salts with nuclear-grade graphite

“…In recent years, many studies have detailed the use of LIBS for elemental depth profiling and mapping. 2–28 The reader is pointed toward a recent review by Jolivet et al for more thorough exposition of published LIBS imaging studies. 22 The LIBS technique involves irradiation of a sample with an intense, focused beam of light from a pulsed laser source.…”

Improving Spatial Resolution by Reinterpreting Dosage for Laser-Induced Breakdown Spectroscopy Imaging: Conceptualization and Limitations

“…It is important to reiterate that the excimer laser system used for the application of the demonstrated approach is beneficial, since the high repetition rate and square aperture enabled the application of the dosage concept in the first place. Additionally, even though solid-state lasers with high pulse energies lead to an improved sensitivity compared to the excimer laser, the ablation rate can be in the micrometer range for 1064 nm Nd:YAG lasers, 29 restricting the layer thickness that can be analyzed using the dosage concept.…”

Application of Laser-Induced Breakdown Spectroscopy for Depth Profiling of Multilayer and Graded Materials

“…This can alter the original material, affecting surface mapping (as shown in Figure 5) and depth profiling [46]. Such alterations are particularly significant when the distance between sampling points is minimal [47,48]. In the case of polymeric materials, there is an additional challenge associated with the high viscosity of the material produced by melting due to the action of the laser beam.…”

“…They also include materials that withstand severe thermal and mechanical loads [31,73,74]. Another set featured in the table comprises superalloy composites [75], metallic coatings [32,43,47], silicon-based photovoltaic cells [45], thin film varieties of solar cells [76][77][78], lithium electrodes [79], and thin catalyst layers deposited on various substrates [80,81]. Furthermore, the table also presents historically significant materials, including archaeological artifacts [20,59,82,83], artwork [59], structural elements from heritage sites [84][85][86], and formulations used to preserve ancient masonry [87].…”

“…(a,c) SEM images showing a single ablation crater formed on Cu (a) [47] and on multilayer Al-Ni-Fe samples (c), where the colors indicate the abundance of the elements Al (violet), Ni (green)and Fe (red) (adapted according to[48] with permission). (b,d) Array of ablation craters formed on Cu (b) (adapted according to[47] with permission) and Al-Ni-Fe samples (d)[48].…”