Measurement and thermodynamic assessment of the phase equilibria in the Mg-Hg-Ga ternary system

Phase relations in the Mg-Hg-Ga ternary system have been experimentally and thermodynamically studied. At first, the isothermal sections of the Mg-Hg-Ga system in the Mg-rich region at 673 K and 473 K were investigated by using powder X-ray diffraction (XRD) and scanning electron microscope (SEM) with X-ray energy dispersive spectroscope (EDS). A ternary compound Mg21Ga5Hg3 of tetragonal structure was detected and its homogeneity was determined. Then, based on the experimental literature, a thermodynamic assessment of the Mg-Hg-Ga ternary system was carried out by the CALPHAD approach. Consequently, a self-consistent set of thermodynamic parameters describing this system was obtained, which leads to a good fit between the calculated and experimental data.