Study on Brazilian 18th century imperial carriage using x-ray nondestructive techniques. (January 2019)

• Record Type: Journal Article
• Authors: Nardes, R.C.; Silva, M.S.; Rezier, A.N.S.; Sanches, F.A.C.R.A.; Gama Filho, H.S.; Santos, R.S.; Oliveira, D.F.; Lopes, R.T.; Carvalho, M.L.; Cesareo, R.; Zanatta, E.M.; Assis, J.T.; Anjos, M.J.
• Is Part Of: Radiation physics and chemistry. Volume 154(2019:Jan.)
• Page Start: 74
• Page End: 78
• Publication Date: 2019-01
• Subjects: Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2018.04.005
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: In this study was verified the presence of gold in the coatings of the emperor D. Pedro's II Berlin device, part of the Imperial Museum of Petropolis collection, Brazil. The perform was evaluation of the thickness of the gold leaf, using the technique of X-Ray Fluorescence, measuring peak intensities (Kα / Kβ or Lα / Lβ) of the elements of interest in the layer. It was possible to verify in the XRF spectra the presence of four elements: Ti, Fe, Au and Pb. The Pb was present in all sampling points, which indicates the presence of lead carbonate (lead-white) as preparation layer. The presence of Au in some sampling points indicates that several parts of the Berlin devices were covered with gold leaf. The presence of Ti and Fe is due to the application of golden mica over the entire length of the berlin device during the process of last restoration. The presence of the mica layer on the gold covering was relevant for gold thickness determination. The average value of the gold thickness obtained was 0.6 ± 0.5 µm, with a coefficient of variation of 83% and a confidence interval of 0.5–0.8 µm (α = 0.05). The values are compatible with the thickness of gold foil normally found in the coating of pieces of wood from the same period that the Berlin device was built. Highlights: The study and characterizations of the gold leaf thickness in historical objects of art. Gold leaf thickness measurements by XRF. The ratio of the intensities of the Lα and Lβ characteristic X-ray lines of lead. We were able to add a bit more history to the story of the imperial horse-drawn carriage of Emperor D. Pedro II/Brazil.