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The Inamori School of Engineering graduate student, Annika Blake-Howland will defend her MS/Glass Science thesis onWednesday, May 6th in Binns-Merrill Hall Room 106 at 10:00A.M
Title of Thesis: ORIGIN OF IRIDESCENCE IN FREDERICK CARDER'S AURENE GLASS: LINKING SURFACE STRUCTURE, HEAVY METAL ENRICHMENT, AND OPTICAL RESPONSE
Copies of Annika's thesis will be on display in BINNS, 160 and McMahon in the CACT Office.
Aurene, an artistic glass developed by Frederick Carder in the early twentieth century, exhibits a distinctive iridescent surface where the structural origin is not fully resolved. This study employs a multi-technique approach including SEM-EDS, Raman spectroscopy, FT-IR microscopy, X-ray diffraction, UV-Vis spectroscopy, and profilometry to investigate the relationship between composition, structure, and optical behavior in Aurene glass.
The results demonstrate that the iridescent region corresponds to a chemically modified surface region approximately =1 �m in thickness, characterized by enrichment in tin and silver relative to the bulk lead-borosilicate matrix. SEM-EDS line scans reveal a steep diffusion gradient, with tin and silver concentrations decreasing to bulk levels within 1 �m or less. XRD analysis indicates the presence of a cassiterite-like SnO2 phase within an otherwise amorphous surface region, while UV-Vis spectra suggest the formation of Ag� nanoparticles, consistent with a broad absorption feature near ~400 nm.
Although Raman and FT-IR measurements are limited by fluorescence, spectral overlap, and spatial resolution constraints, they support an overall understanding of the structure of the lead-borosilicate bulk glass. Together, these results support a model in which Aurene's iridescence arises from the combined effects of thin-film interference due to refractive index variation across a submicron gradient, plasmonic contributions from silver nanoparticles, and multiscale surface morphology.
These features are consistent with surface-limited redox and oxidation reactions during production, as documented in Frederick Carder's archival papers. Overall, this work establishes a framework for Aurene glass in which rapid surface reactions produce a thin, compositionally heterogeneous layer responsible for its characteristic optical effects, linking archival descriptions with modern materials characterization.
Attachment: Blake-Howland Abstract
Submitted by: Eliza Sidenstecker
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