Tátrai Vilmos szerk.: A Szépművészeti Múzeum közleményei 95. (Budapest, 2001)

TÓTH, MÁRIA - BERTÓTI, IMRE - MOHAI, MIKLÓS - FÓRIZS, ISTVÁN -VOZIL, IRÉN: Material analysis of the bronze statuette of Imhotep

MATERIAL ANALYSIS OF THE BRONZE STATUETTE OF IMHOTEP The aim of this study was to identify the chemical elements of various parts of the statuette of Imhotep from the Egyptian Collection of the Museum of Fine Arts in Budapest. It was reasonable to assume that the various parts of the statuette were made of alloys with different composition. The question was whether the chair and its base which are fixed firmly together, as well as the body and the footstool which are also fixed together, have the same or different chemical composition. In order to clarify this issue a phase analysis by X-ray powder diffraction

1 (XRD), X-ray excited photoelectron spectroscopy

2 (XPS) and electron probe microanalysis

3 (EPMA) were carried out. The phase composition, the quality and the relative ratio of the crystalline phases of the bronze were determined by XRD, while the chemical composition was studied by XPS and EPMA. The available sample was not enough for a reliable analysis of the carbonaceous impurities and the oxidation status of the metals. Therefore, only the data of elemental compositions were used for the measurements for interpretation. Morphological features (fracture and surface morphology) and at certain locations the chemical composition of the samples were investigated by EPMA. The material testing was carried out by Mária Tóth, István Fórizs (Hungarian Academy of Sciences (HAS) Laboratory for Geochemical Research, Budaőrsi út 45., Budapest 1112, Hungary), Imre Bertóti, Miklós Mohai, (Research Laboratory of Materials and Environmental Chemistry, Chemical Research Center of HAS, Pusztaszeri út 59-67., Budapest 1025, Hungary). 1 XRD, Philips X-ray diffractometer, Cu Koc radiation, 45 kV, 35 mA, 1° divergency slot, graphite monochromator, APS software 2 XPS, Kratos XSAM 800 type, Mg Ka source, fixed retarded ratio working mode, detection in the kinetic energy region of 50 - 1300 eV. 3 Electron probe microanalyser JEOL JXA Superprobe 733, accelerating voltage: 30 kV beam curent: 30 nA, detection time: 40 sec. Results of the EPMA studies are presented in the following form: Energy dispersive microanalysis (EDS) spectra (Figures No. 3 and 4 ). Horizontal axis: characteristic X-ray energy of the excited elements. Vertical axis: X-ray count rate proportional to the amounts of the present elements. Morphological features of the samples are shown in SEI (secondary electron image) (fig. 29). In this working mode, secondary electrons coming out of the excited elements are used. This type of image is appropriate to study the special morphology.