Quantitative characterisation of damage mechanisms in ancient ceramics by quantitative X-ray powder diffraction, polarisation microscopy, confocal laser scanning microscopy and non-contact mode atomic force microscopy

Abstract

Ceramic technology is civilisation's oldest tradition and one of our most current areas of knowledge. Pottery, ceramics, and their industrial production materials have been rooted in the historical and cultural structure of a nation and civilisation for thousands of years and retain their importance today. The origin of the surveyed material in this paper relates to areas of the Elamite Period (1500 BC) in South-West Iran 10 The main purpose of the identification is to pay attention to the textural formation of the material, which is dependent on the mineralogical chemical performance in such systems. In this investigation, the texture of damage and phase segregation was determined. The phase analyses of crystalline composition were determined by quantitative X-ray powder diffraction (QXRD) measurements with Rietveld refinement. 16 The results were matched with microscopic methods in order to arrive at a chemical petrological conclusion. The chemical compositions of the phases and the variation of elements between boundaries and the core were obtained by correlation of QXRD and X-ray fluorescence results and verified through EDX measurements. According to XRD polarisation microscopy studies, the research materials can be divided into two groups according to their matrix structure. 19 The first group displays a calcareous matrix, which mainly consists of CaCO 3 with a minor content of SiO 2 . The second group consists mainly of SiO 2 and other silica compositions, such as alkali-feldspars, plagioclases and pyroxene. With respect to thermodynamic stability of pyroxene, the stability area of the solid solution in such systems varies between 750 and 870uC. Here, AFM in non-contact mode was carried out. The aim of this combined method was to confirm the damage process with regard to the structural conversion in the interface between selected minerals and the matrix (quartz, plagioclase, Kali-feldspar). Thus it was ultimately possible to obtain a quantitative characterisation of the micro-and nanostructure of these historical materials. As a result of this data, it is possible to define much more precise requirements for modern methods of restoration of materials, 12 in order to gain higher durability and rentability cycles.It is possible to explain the techniques which have been used in ancient times in terms of material science methods, with the so called 'ceramography'. In fact, the word ceramic is of Greek origin and means potter's earth; however the tradition is much older. Traditional ceramics are those derived from naturally occurring raw materials and include clay based products. These were the most readily available raw materials for the ancient potters. It means that pottering might be actually the human development reference. Ceramics were the first products of people who sought materials which were required to demonstrate good plasticity behaviour in forming, high durability during firing, and an aesthetically pleasing end result. Emami et al. Surface modification of ancient ceramics by means of CLSM, AFM a...

Characterization of Ancient Ceramic Matrices with High Resolution Microscopy Methods

“…XRF results proved that these kinds of ceramics are SiO 2 rich ceramics ( Fig. 6) and there exist large distinction between them and the ceramics from south-west Iran (Emami et al, 2008). Their matrices are glassy and consist of many crystal fragments that have a magmatic origin.…”

“…For using the Rietveld method in order to obtain a better quality of fit in the calculation such, it is better to refine other phases such as muscovite or analcim, with quartz. Calcite appeared with the best orientation at d [Å] = 3,04 (100), 2,28 (111) and 1,92 (011) and 2θ = 29,2° &39,4° & 47,0° (Emami et al, 2008). The next important group within these materials are the chain silicates, such as pyroxenes.…”

“…The homogeneous or inhomogeneous of the material's surface, and the frequent distribution of such elements such as Fe, Mg, Ca, can give us a result about the discolouring of the ceramic bodies and, on the other hand, the roughness and therefore potential diffusions under the microscope (Emami et al, 2008). Ceramic texture been used to characterize many aspects of atomic and molecular arrangements.…”

“…Extensive solid solution is possible among members of the calcic, calcic-sodic and sodic pyroxenes. The best preferred orientation is over 2θ = 29-31° and 34,5-36,5° (Emami et al, 2008). The next important calculated phases are the framework silicates, the so called feldspars & plagioclases.…”

“…To characterization ceramic matrices, some samples of ancient ceramic pieces from Persepolis (Takht-e Djamshid) world heritage site were selected. These samples were examined with Atomic Force microscopy (AFM-PFM) (Emami et al, 2008& Maggetti, 1982.…”