Thermodynamic properties of gadolinium disilicide

Experimental investigation and thermodynamic modeling of the Gd–Si system

“…The calculated results are in reasonable agreement with the reported data [13][14][15]. The calculated Gibbs energy of solids at 800 K and the reported data by Lukashenko and Polotskaya [18], Sidorko and Polotsokaya [17], and Uspenskaya et al [20] are shown in Fig. 10.…”

“…However, as shown in Figs. 11 and 12, there are large discrepancies between the calculation and experimental data [16,18,19] for the enthalpy and entropy of formation of solids at 800 K, especially on the Gd-rich side. The calculated enthalpies of mixing of the liquid phase at 1770 K together with the experimental data of Kanibolotsky et al [22,24] and Beloborodova et al [23] are shown in Fig.…”

“…The enthalpy of formation for Gd 5 Si 3 [13,14], Gd 5 Si 4 [13], GdSi [13,15], Gd 2 Si 3 [13] and GdSi 2−x [13,14] were investigated by Usenko et al [13] by solution drop calorimetry, and Meschel and Kleppa [14,15] by direct-synthesis calorimetry. The Gibbs energy, enthalpy and entropy of formation of the compounds Gd 5 Si 3 [16,17], Gd 5 Si 4 [16,17], GdSi [16], Gd 2 Si 3 [16] and GdSi 2−x [16,18] were investigated by Lukashenko et al [16,18], Sidorko and Polotsokaya, [17] and Lukashenko and Polotskaya [19] by measuring the emf of high-temperature galvanic cells in the temperature range of 600-960 K and the Gibbs energy of formation of Gd 3 Si 5 was calculated by Uspenskaya et al [20]. The enthalpies of mixing of Gd-Si alloys have been measured by high-temperature calorimetry on Si-rich side (94-100 at.% Si) at 1800 K [21], in the composition ranges 0 < x Si < 0.2 and 0.8 < x Si < 1, and 0 < x Si < 0.2 and 0.7 < x Si < 1 at 1760 K [22,23], and those over the entire composition range at 1770 ± 5 K [24].…”