Thermodynamic properties of silicides. VI. Pentamolybdenum trisilicide (Mo5Si3). Fluorine combustion calorimetric determination of the standard molar enthalpy of formation at the temperature 298.15 K

Thermodynamic properties of molybdenum silicides by molten electrolyte EMF measurements

“…Assessed value by Barin [4] for Mo 5 Si 3 shows relatively high temperature dependence. The difference between the value reported by Tomaszkiewicz et al [5,6] and the present results are less than 10 kJ for Mo 3 Si and Mo 5 Si 3 . The difference between these assessed data and the present results might have been caused by the selection of the heat capacity and the standard enthalpy of formation for each silicides.…”

“…EMF measurements using zirconia electrolyte were performed by Ohmori et al [2] and they reported these values for Mo 3 Si and Mo 5 Si 3 at temperatures 1150-1450 K. However, the results of these works do not agree with each other. Additionally, assessed and calculated values of the standard free energies of formation for these silicides by Hultgren et al [3], Barin [4] and Tomaszkiewicz et al [5,6] are also inconsistent. The standard enthalpies of formation at 298 K, f H • * Corresponding author.…”

“…Searcy and Tharp [7] measured the silicon vapor pressure at temperatures from 1926 to 2261 K by Knudsen effusion method and obtained values by combining the heat capacity data. Robbins and Jenkins [8], Maslov et al [9], Tomaszkiewicz et al [5,6], O'Hare [10] and Meschel and Kleppa [11] used calorimetric method for determination of f H • (298) values. However, difference in these results is not negligible.…”

Thermodynamics of silicon nitride. I. Standard molar enthalpies of formation ΔfHmoat the temperature 298.15 K of α-Si3N4and β-Si3N4

“…In practice, Si 3 N 4 was placed in a tungsten saucer that sat atop a nickel crucible that, in turn, rested on the lid of the inner chamber. We used (21,27) a similar arrangement in the past. As the F 2 entered the combustion chamber, it ignited the Si 3 N 4 .…”

Thermodynamic properties of vanadium silicides II. Standard molar enthalpy of formationΔfHmo(298.15 K) and reassessed thermodynamic properties of trivanadium monosilicide (V3Si)

“…Previous experience has shown (11) that silicides of transition metals are usually suitable candidates for study by fluorine bomb calorimetry, in that well-defined combustion products are obtained, with the metal reacting to form the fluoride of highest oxidation state, and the silicon SiF 4 (g). The study of VSi 2…”