Thermal and topographical study of some phase transitions in the Au- 50.wt% Cu and Au-15wt.% Cu-35wt. %Ag systems at low temperature

Abstract

The gold-copper alloys are among the first investigated alloys in the humain history. The aim of this work is to study the new reaction in the binary and the ternary 12-carrat gold alloys at low temperature to determine the nature of some phase transition using X-ray diffraction (XRD) and thermal techniques which are differential scanning calorimetry (DSC) and differential dilatometry. Furthermore, morphological techniques have been used like scanning electron microscopy (SEM) and scanning tunnel microscopy (STM). In addition to X-ray photon electron spectroscopy (XPS) ending by confirming it by grazing incidence Xray diffraction. Finally, we confirmed the presence of such anomaly at low temperature and we found that it is probably about the precipitation of coper oxide nanoparticles at these low temperatures on sample surfaces.