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SmFeGe2O7 germanate has been synthesized by solid-state reactions from stoichiometric mixtures of starting oxides using multistage sintering in the temperature range 1273‒1473 K. The effect of temperature on the heat capacity of the compound has been studied by differential scanning calorimetry. On the basis of the dependence Cp = f(T), the thermodynamic properties of this compound have been calculated. [ABSTRACT FROM AUTHOR]

Oxides Y0.65Pr0.35BiGeO5 and Y0.65Nd0.35BiGeO5 have been synthesized by a ceramic method. The heat capacity of fine crystalline samples has been studied in the range 350-1000 K by differential scanning calorimetry. The Cp = f(T) dependences can be described by the Maier-Kelley equation. The thermodynamic functions of these oxides—changes in enthalpy, entropy, and reduced Gibbs energy—have been calculated from the experimental data on high-temperature heat capacity. [ABSTRACT FROM AUTHOR]

ErInGe2O7 and TbInGe2O7 have been synthesized from the parent oxides by a ceramic method through the multistep annealing in air in the temperature range 1273–1473 K. The high-temperature heat capacity of these oxides has been measured by the differential scanning calorimetry method (350–1000 K). Their thermodynamic properties have been calculated from the experimental dependences Cp = f(T). [ABSTRACT FROM AUTHOR]

The oxide compound PbLa(GeO)(VO) with an apatite structure has been synthesized by a ceramic method. The effect of temperature on the molar hear capacity of polycrystalline samples in the temperature range 320-1000 K has been studied by differential scanning calorimetry. The results have been used to calculate the thermodynamic functions of the synthesized compound. [ABSTRACT FROM AUTHOR]

Erbium titanate with a pyrochlore structure has been synthesized by a ceramic method from stoichiometric ErO-TiO mixtures at 1673-1773 K. The high-temperature heat capacity of ErTiO (320-1000 K) has been studied by differential scanning calorimetry. The thermodynamic functions of this oxide compound-enthalpy and entropy changes and reduced Gibbs-have been calculated from the experimental dependence C = f( T). [ABSTRACT FROM AUTHOR]

Ternary oxide GdBiGeO was synthesized by a ceramic method. The heat capacity of crystalline gadolinium bismuth germanate as a function of temperature in the range 373-1000 K has been studied by differential scanning calorimetry. It has been demonstrated that the temperature dependence of the heat capacity can be described by the classical Maier-Kelley equation. From the experimental C = f( T) data, the thermodynamic functions (the change in enthalpy and entropy) of ternary oxide GdBiGeO have been calculated. [ABSTRACT FROM AUTHOR]

The effect of temperature within the range 379-1026 K on the specific heat of thulium orthovanadate TmVO obtained by solid-phase synthesis was studied by differential scanning calorimetry. From the experimental dependence C = f( T), which is described by the equation C = (136.46±0.47) + (15.5±0.5) × 10 T - (17.5±0.6) × 10T, the thermodynamic functions of the oxide compound were calculated. [ABSTRACT FROM AUTHOR]

The molar heat capacity of PbVO and PbVO in the temperature range 350-1000 K was measured by differential scanning calorimetry. It was determined that the plot C = f( T) for PbVO has an extremum within the range 416-516 K, which is due to a phase transition. A correlation was found between the heat capacity and composition of oxides in the PbO-VO system. The data obtained allowed one to predict the specific heat capacity value for Pb(VO). [ABSTRACT FROM AUTHOR]

The heat capacities of PbVO and Pb(VO) as a function of temperature in the range 350-965 K have been studied by the differential scanning calorimetry method. The C = f( T) curve for PbVO is described by the equation C = (230.76 ± 0.51) + (73.60 ± 0.50)×10 T − (18.38 ± 0.54)×10 T in the entire temperature range. For Pb(VO), there is a well-pronounced extreme point in the C = f( T) curve at T = 371.5 K, which is caused by the existence of a structural phase transition. The thermodynamic properties of the oxide compounds have been calculated. [ABSTRACT FROM AUTHOR]

Erbium stannate ErSnO and thulium stannate TmSnO with a pyrochlore-type structure were produced by solid-phase synthesis by calcining stoichiometric mixtures of the respective oxides in air at 1473 K for 240 and 200 h. The high-temperature heat capacity of Er2Sn2O7 and TmSnO was studied by differential thermal calorimetry at 353-1000 K. From the experimental dependences C = f( T), the thermodynamic functions (enthalpy change, entropy change, and reduced Gibbs free energy) of oxide compounds were calculated. [ABSTRACT FROM AUTHOR]

The molar heat capacity of BiVO has been measured in the range 356-980 K by the differential scanning calorimetry method. There is an extreme point in the C = f( T) curve at about T = 532 K, which is caused by the existence of a phase transition. The thermodynamic properties of bismuth orthovanadate have been determined from the experimental data. [ABSTRACT FROM AUTHOR]