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Thermodynamic properties of polycrystalline powders of ruthenium dichalcogenides have been studied using calorimetric isobaric heat capacity measurements in a wide temperature range. The adiabatic and differential scanning calorimetry data for ruthenium disulfide and ruthenium diselenide have been used to determine standard thermodynamic functions (heat capacity, entropy, enthalpy increment, and reduced Gibbs energy) of these compounds in the range 10–965 K. At 298.15 K, the functions of RuS2 are as follows: = 60.82 ± 0.12 J/(K mol), S° = 56.05 ± 0.11 J/(K mol), Н°(298.15 K) − Н°(0) = 9.75 ± 0.02 kJ/mol, and Ф° = 23.34 ± 0.05 J/(K mol). For RuSe2, we have obtained = 69.96 ± 0.14 J/(K mol), S° = 80.62 ± 0.16 J/(K mol), Н°(298.15 K) − Н°(0) = 13.05 ± 0.03 kJ/mol, and Ф° = 36.85 ± 0.08 J/(K mol). The data obtained above 298 K have been used to determine empirical coefficients of the Maier–Kelley and Khodakovsky equations. The absolute entropies obtained in this study for the ruthenium dichalcogenides, in combination with literature data, have made it possible to evaluate the Gibbs energy of formation of RuS2(cr) and RuSe2(cr) at 298.15 K. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis of crystalline ruthenium ditelluride (RuTe2) and its thermodynamic properties in the range from 10 to 965 K, evaluated from its isobaric heat capacity Cp determined using calorimetry. At low temperatures, between 6.86 and 335.11 K, the heat capacity of the synthesized material—pure, free of impurities and foreign phases—was determined by adiabatic calorimetry. In the range 315.3–965.3 K, Cp was determined by differential scanning calorimetry. The data obtained above 298 K have been used to determine empirical coefficients of the Maier–Kelley and Khodakovsky equations. In the range 10–965 K, we have evaluated the standard thermodynamic functions: heat capacity, entropy, enthalpy increment, and reduced Gibbs energy. At 298.15 K, we have obtained = 72.43 ± 0.14 J/(K mol), S° = 94.94 ± 0.19 J/(K mol), Н°(298.15 K) − Н°(0) = 14.60 ± 0.03 kJ/mol, and Ф° = 45.97 ± 0.09 J/(K mol). Using the absolute entropy determined by us and data in the literature and handbooks, we have estimated the standard Gibbs energy of formation of RuTe2: ΔfG°(RuTe2, cr, 298.15) = −130.5 ± 2.9 kJ/mol. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis of crystalline platinum ditelluride, PtTe2, a synthetic analog of the mineral moncheite, and its thermodynamic properties. Using the isobaric heat capacity of PtTe2 determined in the range 2–305 K by the relaxation and adiabatic calorimetry methods, we have evaluated its standard thermodynamic functions: entropy, enthalpy increment, and reduced Gibbs energy. The following parameters have been obtained for PtTe2 at 298.15 K: = 75.11 ± 0.15 J/(K mol), S° = 121.5 ± 0.2 J/(K mol), Н°(298.15 K) − Н°(0) = 16.69 ± 0.03 kJ/mol, and Ф° = 65.55 ± 0.13 J/(K mol). Using data in the literature and handbooks, we have estimated the standard Gibbs energy of formation of PtTe2: ΔfG°(PtTe2, cr, 298.15) = –75.4 ± 0.8 kJ/mol. Fractal analysis of the heat capacity data indicates that PtTe2 has a layered structure and that its Debye temperature is 250 K. [ABSTRACT FROM AUTHOR]

The isobaric heat capacity of p-SmZrO (pyrochlore phase) has been determined in the temperature range 10-1400 K using adiabatic, differential scanning, and relaxation calorimetry, and its enthalpy increment, entropy, and reduced Gibbs energy have been calculated with allowance for the contributions of its low-temperature magnetic transformations. [ABSTRACT FROM AUTHOR]

The low-temperature heat capacity of DyO · 2ZrO and HoO · 2ZrO has been determined by adiabatic calorimetry in the temperature range 10-340 K. The results have been used to calculate the entropy, enthalpy increment, and reduced Gibbs energy of the zirconates without taking into account their low-temperature magnetic transformations. [ABSTRACT FROM AUTHOR]

The temperature-dependent heat capacity of aluminum oxynitride has been determined by adiabatic calorimetry in the range 0-340 K. Smoothed heat capacity data have been used to calculate its thermodynamic functions: entropy, enthalpy increment, and reduced Gibbs energy. The results are C(298.15 K) = 891.0 ± 1.8 J/(mol K), S(298.15 K) = 614.4 ± 1.2 J/(mol K), H(298.15 K) − H(0) = 117.3 ± 0.2 kJ/mol, and Φ(298.15 K) = 221.0 ± 1.8 J/(mol K). [ABSTRACT FROM AUTHOR]

The thermodynamic activities of brass CuZn17Si3 components are calculated. The potential-pH diagrams for the brass CuZn17Si3-HO system for 25°C, a total air pressure of 1 bar, and various ions activities in solution are plotted. The thermodynamic features of the chemical and electrochemical stability of brass CuZn17Si3 are analyzed. It is shown that high corrosion resistance of brass is achieved with respect to the formation of a protective film of ZnSiO on its surface. [ABSTRACT FROM AUTHOR]

The heat capacity of LiNiO ( x = 0.40–0.76) oxides has been measured using an adiabatic calorimeter, and their thermodynamic functions have been determined. The results indicate that the lithium nickelate solid-solution series contains a two-phase region and that near-stoichiometric LiNiO has a layered structure, in accordance with earlier results. [ABSTRACT FROM AUTHOR]

The heat capacity of Ga2Te3 is measured from 9 to 310 K using adiabatic calorimetry. The smoothed heat capacity data are used to evaluate temperature-dependent thermodynamic functions (entropy, enthalpy increment, and reduced Gibbs energy) of Ga2Te3. Its thermodynamic properties under standard conditions are C (298.15 K) = 119.3 ± 0.2 J/(K mol), S 0(298.15 K) = 209.8 ± 0.4 J/(K mol), H 0(298.15 K) – H 0(0) = 27.19 ± 0.05 kJ/mol, and Φ0(298.15 K) = 118.6 ± 0.2 J/(K mol). The Debye characteristic temperature of Ga2Te3 evaluated from the heat capacity data is 280 ± 20 K. [ABSTRACT FROM AUTHOR]

The heat capacity of GaTe is measured from 6.8 to 337.95 K using adiabatic calorimetry. The results are used to calculate the heat capacity, entropy, enthalpy increment, and reduced Gibbs energy of GaTe in the temperature range 10–320 K under standard conditions. The 298.15-K thermodynamic properties of GaTe are C (298.15 K) = 48.96 ± 0.10 J/(K mol), S 0(298.15 K) = 81.30 ± 0.16 J/(K mol), H 0(298.15 K) − H 0(0 K) = 10.84 ± 0.02 kJ/mol, and Φ0(298.15 K) = 44.95 ± 0.09 J/(K mol). [ABSTRACT FROM AUTHOR]

The heat capacity of Ga2Se3 is measured from 14 to 320 K by adiabatic calorimetry. The smoothed heat capacity data are used to evaluate temperature-dependent thermodynamic functions (entropy, enthalpy increment, and reduced Gibbs energy) of gallium selenide. Under standard conditions, the thermodynamic properties of Ga2Se3 are C (298.15 K) = 120.8 ± 0.2 J/(K mol), S 0(298.15 K) = 180.4 ± 0.4 J/(K mol), H 0(298.15 K) - H 0(0) = 25.32 ± 0.05 kJ/mol, and Φ0(298.15 K) = 95.52 ± 0.19 J/(K mol). The Debye characteristic temperature of Ga2Se3 evaluated from heat capacity data is 340 ± 10 K. [ABSTRACT FROM AUTHOR]

The heat capacity of ScVO has been determined by adiabatic calorimetry at temperatures from 14.52 to 347.13 K, and smoothed heat capacity data have been used to evaluate its thermodynamic functions (entropy, enthalpy increment, and reduced Gibbs energy). At 298.15 K, the thermodynamic functions of scandium orthovanadate are C(298.15 K) = 110.5 ± 0.1 J/(mol K), S(298.15 K) = 110.9 ± 0.1 J/(mol K), H(298.15 K) − H(0) = 18.53 ± 0.01 kJ/mol, and Φ(298.15 K) = −[ G(298.15 K)/298.15] = 48.75 ± 0.12 J/(mol K). The calculated Gibbs energy of formation of scandium orthovanadate from its constituent elements is Δ G(ScVO, 298.15 K) = −1644.0 ± 2.2 kJ/mol. [ABSTRACT FROM AUTHOR]

The heat capacity of GdVO has been determined by adiabatic calorimetry in the range 5-345 K. The present experimental data and earlier results have been used to evaluate the thermodynamic functions of gadolinium orthovanadate ( C( T), S( T), H( T) − H(0), and Φ( T)) as functions of temperature (5-350 K). Its Gibbs energy of formation is determined to be Δ G(GdVO, 298.15 K) = −1684.5 ± 1.6 kJ/mol. [ABSTRACT FROM AUTHOR]

The heat capacities of lanthanum and lutetium orthovanadates have been measured at temperatures from 7 to 345 K using an adiabatic calorimeter. No anomalies have been detected in the heat capacity data. The thermodynamic functions ( C( T), S0( T), and H0( T) − H0(0)) of the two compounds have been calculated in the temperature range studied, and their Debye characteristic temperatures have been estimated. [ABSTRACT FROM AUTHOR]

The heat capacity of dysprosium orthovanadate has been determined by adiabatic calorimetry in the range 6.12-343.26 K. The present and earlier data have been used to calculate the thermodynamic functions of DyVO in the temperature range 0-350 K. We have determined the absolute entropy and Gibbs energy of formation of dysprosium orthovanadate: S(298.15 K) = 148.34 ± 0.11 J/(mol K), Δ G(298.15 K) = −1671.6 ± 2.1 kJ/mol. An anomaly has been detected at temperatures below 42 K, due to the Jahn-Teller phase transformation ( T = 14.42 K). We have determined the thermodynamic characteristics of the transformations in the temperature range 0-42.63 K. [ABSTRACT FROM AUTHOR]