High‐sensitivity Raman imaging of the surface of casted glass plates. (2nd March 2021)

• Record Type: Journal Article
• Authors: Jacquemin, M.; Simon, P.; Canizarès, A.; Hennet, L.; Bessada, C.; Skrelic, D.; Gouillart, E.; Burov, E.
• Is Part Of: Journal of Raman spectroscopy. Volume 52:Number 5(2021)
• Page Start: 1048
• Page End: 1054
• Publication Date: 2021-03-02
• Subjects: glass processing -- glasses -- Raman imaging; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.6086
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract: Glass manufacturing processes are prone to induce local fluctuations of the glass properties, to which Raman spectroscopy is highly sensitive. In this work, Raman imaging is used to investigate the homogeneity of the Raman response at the surface of casted aluminosilicate glass pieces. Samples were probed at constant focus depth across 7 × 7 cm 2 surfaces using 500 μm spatial steps, resulting in unusually large and detailed Raman images. We show that the extent of modification of the Raman response is small across the scanned area and that the information is mostly carried by the spatial representation of properly selected Raman parameters. Specifically, detailed macroscopic patterns correlating to the glass casting process were obtained from Raman parameters of two distinct Raman modes: the Si‐O stretching mode involving Q 2 tetrahedral units, and the Si‐O‐Si bending vibrations envelope in the low‐wavenumber range. The contrasts on the Raman images are assigned to fine local variations of fictive temperature (and hence of cooling rate) and chemistry resulting from the manufacturing process. From the evolution of these parameters across the surface of the sample, we were able to identify areas consisting of material from different stages of the casting. Structural and chemical changes originating from the manufacturing process are therefore printed at the surface of the glass pieces, and their fingerprint revealed by Raman imaging. Abstract : Raman imaging was used to probe the homogeneity of the Raman response at the surface of large casted glass samples. The reconstructed images evidence macroscopic patterns from small variations of the Si‐O bending and stretching modes. These fluctuations show an obvious correlation with the casting process and are interpreted as differences in cooling rate and chemistry. Structural changes originating from the manufacturing process are therefore printed at the surface of the glass pieces, and their fingerprint revealed by Raman imaging.