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[en] This study presents the preliminary results of investigation of the types and dynamics of paramagnetic centres in lime mortars from Sveta Petka church in Budinjak, Croatia, using Electron Spin Resonance (ESR) spectroscopy. The excavation in Budinjak discovered a very unique four lobed plan object Sveta Petka, with no additional finds or reliable historical records about the time of its construction. The lime mortars from the church were chosen for analysis in order to characterize the building material and to verify the site chronology by dating them. Lime mortar is valuable but problematic material for luminescence and radiocarbon dating. This type of material has not been dated before using ESR; therefore, careful studies are required to identify the useful paramagnetic centres. The ESR approach suggested in this work concentrates on a calcium carbonate signal. All samples were γ-irradiated in 60C bomb with the doses of 1, 10, 20, 50, 80 and 100 kGy. In all spectra signals from Fe3+ and Mn2+ ions have been observed. Paramagnetic centres which give the ESR signals may be interpreted as CO2−, CO3−, CO33−, HCO32−, SO2−, SO3−, PO2− and PO32− species. However, all spectra are complex and signals are interfering; therefore, computer resolution enhancement method will be needed in further research. The changes in ESR signals amplitude measured at magnetic field range about 3440–3450 G were analysed versus the dose of irradiation, using Mn2+ signals as a reference. Exponential growth of the curve and saturation for doses above 20 kGy were observed; therefore, irradiation with smaller doses is required. These preliminary studies will be helpful in future attempts of dating lime mortars by ESR method.
[en] Highlights: • Nanolaminate thin films of Al2O3/TiO2 with different bilayer density were prepared by ALD method. • A new multidimensional reconstruction method was implemented to analyze the nanomechanical response of the samples. • Mechanical response of the nanolaminates showed to be improved by layer thickness and follow the behavior of a nanocomposite coating. • The method implemented allows the reconstruction of 4D mechanical data at the nanoscale. A novel method of nanomechanical testing of multilayered Al2O3/TiO2 nanolaminates was implemented by the nanoindentation technique. The indentation data were reconstructed and filtered by a statistical analysis algorithm and presented as a function of the penetration depth of the indenter. Results show the increment of mechanical properties on the laminates as a function of the amorphous interfaces of the individual layers and the effective control of the wear rate of the structures for further applications. The results presented show both important insights on the mechanical behavior of nanolaminates and the further applicability of the reconstruction model for error reduction on mechanical testing of nanolaminate samples.