Structural studies of the brass ingots from the Shcherbet historical complex of the Lower Kama region: neutron diffraction and tomography studies

The structural characteristics and phase composition of several ancient brass ingots obtained in the archeological Shcherbet complex has been studied using neutron diffraction and tomography methods. The XRF analysis and neutron diffraction provide high zinc content up to 30 wt.%. The neutron tomog- raphy yielded 3D data of the spatial distribution of chemical elements in the brass alloy of the studied ingots, as well as inner voids and cavities as a possible result of the gas output during casting process. The patina, as a cuprite phase, occupy volumes to 8 % of the volumes of the ingots

Structural Studies of the Qarakhanid Dirham Using X-Ray Diffraction and Neutron Tomography Methods

Abstract: The structure and spatial distribution of corrosion in the volume of the medieval Qarakhanid dirham dated the X–XII century A.D. (Anno Domini) has been investigated using non-destructive structural X-ray diffraction and neutron tomography methods. The phase composition and their spatial distribution inside the coins were obtained. The main phase of the studied dirham is the silver-copper alloy with copper fraction dominance up to 74 wt %. The basic phases of the corrosion fraction are cuprite Cu2O, tenorite CuO and chalcocite Cu2S. The non-uniform distribution of the corrosion penetration in the coin bulk was constructed

Studies of Coins of Medieval Volga Bulgaria by Neutron Diffraction and Tomography

© 2020, Pleiades Publishing, Ltd. Abstract: The phase composition and spatial distribution of chemical components in the volume of coins of medieval Volga Bulgaria are studied using the neutron-diffraction- and neutron-tomography methods. Two coins belonging to different time periods of this medieval state are studied: a Samanid multidirham dating from the first half of the 10th Century and a silver dirham dating from the period of the reign of the Bulgarian emir Bulat-Timur. It is established that both coins consist of a copper-silver alloy. In the Samanid multidirham, the average volume contents of copper and silver are found to be about 50%. Minor spatial variations in the chemical composition are found in the volume of the multidirham under study. It is established that the volume average silver content in the Bulat-Timur dirham is about 95%

Non-destructive and micro-invasive techniques for characterizing the ancient roman mosaic fragments

© 2020 by the authors. The color characteristics, vibration spectra, phase and mineral composition, internal structural organization of several fragments of the ancient Roman mosaics from the Roman Mosaic Museum, Constanta, Romania were studied by non-destructive (Chromatic analysis, Neutron Diffraction, Neutron Tomography) and micro-invasive techniques (Optical Microscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy, Raman Spectroscopy, Wavelength Dispersion X-ray Fluorescence). These investigations were performed in order to characterize the original Roman mosaic fragments. The major and minor phase components of the studied mosaic fragments were determined, the crystal structure of the main phases was analyzed, and their three-dimension spatial arrangement was reconstructed. The similar composition of the major phases of all mosaic fragments can indicate a generic recipe for making mosaic elements, but minor phases were presumably added for coloring of mosaic pieces. Some degradation areas inside the volume of the mosaic fragments were found by means of neutron diffraction and neutron tomography methods. These degradation areas are probably related to the formation of iron hydroxides during chemical interactions of mosaic fragments with the sea and urban polluted atmosphere