DOI: 10.20350/digitalcsic/14502
title: Dataset for the paper “Oujja, M., Palomar, T., Martínez-Weinbaum, M., Martínez-Ramírez S., Castillejo, M. 2021. Characterization of medieval-like glass alteration layers by laser spectroscopy and nonlinear optical microscopy. Eur. Phys. J. Plus 136, 859;"

description: The study was undertaken in six medieval-like model glass samples UG (unaltered glass), MAK, MAR, MTA, MTB and MTN subjected to various environmental and atmospheric conditions in order to generate alteration layers of different characteristics. A potash-lime silicate glass, with composition similar to that of medieval glasses, was melted at 1400 °C during two hours, poured in a brass mould of rectangular cross section and annealed at 650 °C. The resulting glass ingot was cut in slices of around 10×10×2 mm3 and then polished using emery paper and an aqueous suspension of cerium oxide to obtain optical quality surfaces. Alteration of the glass slices was conducted by exposure to five different laboratory corrosion tests. This dataset consists of images of the samples; Laser-induced Breakdown Spectrocopy (LIBS) spectra; Laser-induced Fluorescence (LIF) spectra; Optical Microscopy (OM); FT-Raman spectroscopy and Multi-Photon Excitation Fluorescence (MPEF) signals obtained with a Nonlinear optical microscopy (NLOM). This information allows characterizing the composition of both body glass and determining the thickness of the degradation layer. Images are presented in JPG. All spectra are presented in cvs format, in a single page. Descriptions of the samples and the experimental conditions in which the spectra were taken and the name of the column values are included at the top of each page. For LIBS, 1 file per sample of elemental composition of the medieval-like glass are included. Each file is composed of 2 columns (wavelength and intensity). For LIF, 1 file per sample of the analysis of fluorescent species of each medieval-like glass are included. Each file is composed of 2 columns (wavelength and intensity). For NLOM, 2 files per sample. In the first one: “MPEF Safe limits”, each file is composed for 10 columns: 2 are for depth (µm) and 8 are for MPEF signal divided in two groups relating to the the power in the sample surface. In the second group of files: “MPEF profiles”, each file is composed for 4 columns: 1 is for depth (µm), 1 is the normalized MPEF intensity, 1 is the Lorentzian fit of depth (µm) and the last one Lorentzian fit. (The thicknesses of the degradation layers of the medieval-like glasses is calculated by the FWHM values of the fits after refractive index corrections). For FT-Raman, 1 file per sample of the analysis of the structure of the medieval-like glass through their vibrational modes is included. Each file is composed of 2 columns (Raman shift and intensity in arbitrary units).
description: This is the experimental dataset used in the paper Eur. Phys. Plus, 136:859 (2021) (http://hdl.handle.net/10261/248668). Historical glass-based objects undergo, since the time of their manufacture, different degradation phenomena that are related to their composition and to the environment to which they were exposed. Three-dimensional (3D) structural and chemical characterization of the degradation layers is important to select the most adequate conservation strategies for glass objects. Optical microscopy (OM) is the most frequently used non-destructive method to examine the surface of historical glasses; however, the 3D structural assessment of alteration layers requires applying the destructive modality of this technique to conduct a cross-sectional study. In this work, a different approach for structural and compositional characterization of alteration layers on model medieval-like glasses is presented, based on the combination of the laser spectroscopies of laser-induced breakdown spectroscopy (LIBS), laser-induced fluorescence (LIF) and FT-Raman, and the emerging, cutting edge technique of nonlinear optical microscopy (NLOM) in the modality of multiphoton excitation fluorescence (MPEF). The results obtained through this multi-analytical photonic approach were compared with those retrieved by examination of the surface and cross sections of the samples by OM and scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM–EDS). While the combination of LIBS, LIF and FT-Raman served to assess the composition of the various alteration layers, the use of MPEF microscopy allowed the non-destructive determination of the thicknesses of these layers, showing for both thickness and composition a good agreement with the OM and SEM–EDS results. Thus, the proposed approach, which avoids sample preparation, illustrates the capability of non-destructive, or micro-destructive in the case of LIBS, laser spectroscopies and microscopies for the in situ study of glass objects of historic or/and artistic value
description: There are 4 files which correspond to each technic employed for the analysis of the six different samples. The file title “LIBS” contains: LIBS_UG; LIBS_MAK; LIBS_MAR; LIBS_MTA; LIBS_MTB; LIBS_MTN. The file for “LIF” contains: LIF_UG; LIF_MAK; LIF_MAR; LIF_MTA; LIF_MTB; LIF_MTN. The file for “FT-RAMAN” contains: FT-RAMAN_UG; FT-RAMAN_MAK; FT-RAMAN_MAR; FT-RAMAN_MTA; FT-RAMAN_MTB; FT-RAMAN_MTN. For the “MPEF” there are two files inside. One title “MPEF safe limits” which contains the documents: MPEF_MAK_SL; MPEF_MAR_SL; MPEF_MTA_SL; MPEF_MTB_SL; MPEF_MTN_SL. And the other called “MPEF profiles” which contains: MPEF_MAK_PROFILE; MPEF_MAR_PROFILE; MPEF _MTA_PROFILE; MPEF _MTB_PROFILE; MPEF _MTN_PROFILE.