Thermodynamic properties of Ge-Ni melts

Thermodynamic modeling of the germanium–nickel system

“…The obtained partial enthalpies of formation agree well with that of [23] measured at 1773 K. The reported enthalpies of mixing agrees well with that of [23] and slightly more exothermic than that of [22]. Sudavtsova et al [11] also evaluated the activities of Ge at 1750 K from the Ge-Ni liquidus coordinates using the Schroeder equation and a modified Hauffe-Wagner method. In addition, the thermodynamic properties of Ge-Ni melts at 1870 K were deduced [11].…”

“…The reported value is slightly less exothermic than that of [23]. More recently, Sudavtsova et al [11] measured the partial enthalpy of mixing of Ni in Ge-Ni melts at 1800 ± 3 K in the concentration range of 0-70 at.% Ni using high temperature isoperibol calorimetry, and deduced the integral enthalpy of mixing by the Darken method. The purities of starting materials are 99.9% Ni and 99.999% Ge.…”

“…The present work takes into account both the experimental data reviewed by Nash et al [6] and those published later [7][8][9][10][11]. Table 1 summarizes the available experimental data in the literature.…”

“…[9] EPMA + [12] XRD + DTA + [13] EPMA − Homogeneity of Ni11Ge19 and Ni3Ge2 [12] XRD + DTA + Enthalpy of mixing of liquid 1800 K, 30-100 at.% Ge [11] High temperature isoperibol calorimetry + 1640-1920 K [19] Knudsen effusion method combined with mass spectrometry − 1288 K, 48. 26- Knudsen effusion + mass spectrometry − 1640-1920 K [19] Knudsen effusion + mass spectrometry + 1623 K [20] Knudsen effusion + mass spectrometry + Standard enthalpy of formation of Ni5Ge3 (298 K) [7] High temperature calorimetry + Curie temperature of FCC (Ni) solid solution [24] Weiss method + a QM means Quoted Mode, which indicates whether the data are used in the parameter optimization: "+ used; − not used.…”

“…The thermodynamic properties for the Ge-Ni melts have been determined in a wide range of concentration and temperature [11,[18][19][20][21][22][23]. Using Knudsen effusion technique and mass spectroscopy, Kant [18] estimated the approximate activities of the Ge-Ni melts in the concentration range of 40-60 at.% Ge at 1700-1800 K, which show large negative deviation from the Raoult's law.…”