Flavia De Nicola deposited LIBS and LIF for the characterization of artistic marbles and Renaissance frescos in the group Restoration studies on Humanities Commons 3 years, 6 months ago
In this work, Carrara marbles, both white and grey, from cave, and fresco laboratory samples have been studied by means of LIF (Laser Induced Fluorescence) and LIBS (Laser Induced Breakdown Spectroscopy). Fresco samples have been prepared in agreement with Renaissance recipes using natural pigments and original materials both for binders and plaster, with the main goal to produce samples as much as possible comparable to roman real mural paintings by Michelangelo period. LIF technique has been already applied in the cultural heritage field as a diagnostic tool because it is no-invasive and no-destructive, remote and in situ applicable, allowing to obtain information of analytical and qualitative interest on different materials by the study of the emission of fluorescence. In this case, the samples have been measured by the LIF scanning system realized at the ENEA, working at both the excitation wavelengths of 266 nm and 355 nm. LIBS has been performed in air at 1064 nm at high resolution in wide spectral ranges. The obtained results demonstrated that the use of both techniques has proved to be helpful for the complete characterization of the materials analyzed in this work. In fact, the LIBS technique was fundamental because of its peculiarity to detect trace elements, that in the Carrara marbles case, constituted of 99% calcite, are the activators of crystal LIF fluorescence indeed. In the mural painting samples the LIBS technique appears to be complementary to LIF to identify binders and discriminate different pigments. In particular, specific concentration ratios by LIBS can help to understand the processes inducing fluorescence phenomena, with attention to the emission bands in the LIF spectra from pure and mixed pigments.