Application of Scanning Electron and Atomic Force Mode Microscopy on inscription from Proto-Elamite period in Tappeh Sofalin

The study of cultural heritage artifacts and the research of a protection and restoration intervention create with - and are often limited to - a complete characterization of their surface. This is not only factual for museum objects, but also for archaeological artifacts, because the object as it was discovered may contain precious unknown information that could be lost by too much aggressive interposition. Clayey tablets and metallic pins from the protohistoric site of Tappeh Sofalin have been studied by means of mineralogical and chemical characterizations. The main part of the research is done in order to get representative interpretation concerning the relationship between these two tools, as the first technological features in writing in this period. Muli-analytical methods were applied for these devotions. ICP-MS carried out in order to have the chemical compositions of trace elements and ESEM was applied for discriminating the distribution of the elements on the surface of the pin and the tablets. The elemental distributions getting a modeling of clustering with respect to the similarities between the elements concentrated on the surface of the pin as well as on the tablets. The clustering of the chemical, mineralogical results from this site is supported by means of surface characterization via AFM microscopy that dedicated information on the use of the pin as equipment appreciated for engraving the surface of tablets. The surface feature of the objects was observed and controlled by the use of AFM. This microscope enables the study of the electrically conductive or insulating specimen without precise coating or preparation; the AFM involves of a microscale cantilever with a sharp angle (probe) at its end which is used to scan the specimen surface. Thanks to very sensitive displacement controls of the specimen and of the tip by piezoelectric tubes, the equipment allows a measurement of the surface topography with a precision of less than one nanometer in height and a few nanometers in lateral position. The AFM is the only method among these that provides the ability to quantify the majority of material types and also the roughness of a surface characteristic and unrivaled three-dimensional spatial resolution. The AFM offers total 3D surface measurement by imaging topography (height), where they can be investigated to determine areal surface roughness parameters; for example statistics on the domain and grain size or their hardness. Comparison of tools for surface characterization can provide the information about materials properties beyond topography. For instance, AFMs can measure a mechanical (e.g., elastic modulus), and functional properties (e.g., piezoelectric response). The surface roughness of archaeological clay based materials altered due to different environmental parameters, but the effect of graving in nanoscale on their surface can be investigated by atomic force microscopy in order to identify the traces of elements which were remained as the residue during the manufacturing process. On the other hand, this investigations help to trace the effects of the originality on the surface of an objects. Quantitative values of the roughness, the lateral correlation length, and the roughness exponent are extracted from the measurement. The results suggest some residual signs of originalities from the clay tablets during the manufacturing processes.