DOI: 10.5281/zenodo.8189628
title: Efficiency of the formation of acid-resistant Calcium-oxalate layers on limestone

description: <strong>Scientific background:</strong> Carbonate-based stone monuments and buildings are susceptible to weathering in acidic environments. To combat surface corrosion and slow down material deterioration, protective coatings that inhibit calcite dissolution have been proposed. The efficiency and integrity of the coatings was studied by measuring sulfur distribution along the treated surface. Such experiment cannot be efficiently performed with standard SSD PIXE detectors due to high overlap between the strong Ca K x-ray escape peaks and S Kα. For that purpose, a new parallel-beam wavelength dispersive (PB-WDS) X-ray emission spectrometer at JSI have been used which achieves high energy resolution in the eV range and is able to measure S distribution on the surface of treated marble samples. <strong>Measurements performed within TNA project:</strong> The new PB-WDS X-ray emission spectrometer at J. Stefan Institute (Ljubljana, Slovenia) was used to map the presence of Sulphur on the surface of 13 marble samples treated with different coatings and after exposure to 2% sulfuric acid. Ge(111) crystal analyzer was used in the spectrometer to record the S Ka signal, the overall scan size was 5 × 5 mm<sup>2</sup>. <strong>Data files:</strong> We are sharing the files produced during measurements. The signal from the detector preamplifier was processed with the XIA DXP-XMAP digital pulse processor. The files are two main formats: Files containing mapping data. The spectrometer was set to the Bragg angle corresponding to the energy of the S Ka emission line. In a .zip folder, with 4 .mca files for every measured point (extension: _0-Si(Li) detector, _2- PB-WDS spectrometer) High energy resolution spectra recorded at selected points on the sample surface. # Filename 1 VES_A1_5.zip Map of S on VES_A1_5 sample. Ge 111, 100X100 points, 50μm step, 4s/point 2 S_X80_Y85.zip Scan over S Ka and Kb peak on the surface of VES_A1_5 sample. Point position x = 80px, y = 85px 3 VES_A3_5.zip Map of S on VES_A3_5 sample. Ge 111, 100X100 points, 50μm step, 4s/point 4 S_X95_Y33.zip Scan over S Ka and Kb peak on the surface of VES_A3_5 sample. Point position x = 95px, y = 33px 5 VES_A1_12.zip Map of S on VES_A1_12 sample. Ge 111, 40x40 points, 125μm step, 5s/point 6 S_X3_Y3.zip Scan over S Ka and Kb peak on the surface of VES_A1_12 sample. Point position x = 3px, y = 3px. Z position optimized to maximum at this point 7 S_X20_Y20.zip Scan over S Ka and Kb peak on the surface of VES_A1_12 sample. Point position x = 20px, y = 20px. Z position optimized to maximum at this point 8 S_X35_Y20.zip Scan over S Ka and Kb peak on the surface of VES_A1_12 sample. Point position x = 35px, y = 20px. Z position optimized to maximum at this point 9 CAR_A1_12.zip Map of S on VES_A1_12 sample. Ge 111, 80x80 points, 65μm step, 4s/point 10 CAR_A1_12_back_side.txt Scan over S Ka and Kb peak on the back surface of CAR_A1_12 sample. 11 VES_A1_12_Washed.zip Sample washed under running water. 2250 eV - 2350 eV; stepsize = 1.00eV; 6s/point or 10s/point for back 12 VES_A2_12.zip Line map of S on VES_A2_12. 10x1 points, 1mm stepsize, 10s/point 13 CAR_A3_5.zip Line map of S on CAR_A3_5. 10x1 points, 1mm stepsize, 10s/point 14 CAR_A1_5.zip Line map of S on CAR_A1_5. 10x1 points, 1mm stepsize, 10s/point1 15 VES_A3_12.zip Line map of S on VES_A3_12. 10x1 points, 1mm stepsize, 10s/point + Map of S on VES_A3_12 sample. Ge 111, 50x25 points, 200μm step, 3s/point 16 VES_A2_5.zip Line map of S on VES_A2_5. 5x1 points, 1mm stepsize, 10s/point 17 CAR_A2_5.zip Line map of S on CAR_A2_5. 5x1 points, 1mm stepsize, 10s/point 18 CAR_A2_12.zip Line map of S on CAR_A2_12. 5x1 points, 1mm stepsize, 10s/point 19 CAR_A3_12.zip Line map of S on CAR_A3_12. 5x1 points, 1mm stepsize, 10s/point
description: TNA project number: 23003171-ST