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.