Thermodynamics Research Center / ThermoML | Thermochimica Acta

Vaporization studies over (NiO + Ni2Te3O8) in the Ni-Te-O system by transpiration thermogravimetry and Knudsen effusion mass spectrometry

Lakshmi Narasimhan, T. S., Nalini, S., Sai Baba, M.
Thermochim. Acta 2015, 600, 67-76
ABSTRACT
Vaporization studies over (NiO + Ni2Te3O8) in the Ni Te O system were carried out by transpiration thermogravimetry (TTG) and Knudsen effusion mass spectrometry (KEMS) in the temperature ranges of 960 1085 K and 850 960 K, respectively. Comparison of total pressures obtained by TTG with that deduced using partial pressures of vaporizing species from KEMS showed a good agreement providing reliable vapor pressures over this phase region. From vapor pressures, enthalpies of solid gas and gasphase equilibria were evaluated. Subsequently, enthalpy and Gibbs free energies of formation of Ni2Te3O8(s) were deduced at 298.15 K: DfHm = 1543 46 kJ mol 1; DfGm = 1294 46 kJ mol 1. A thermochemical assessment was made to examine the possibility of formation of the ternary Ni2Te3O8(s) phase on stainless steel clad of mixed-oxide fuelled fast breeder nuclear reactors.
Compounds
# Formula Name
1 Ni nickel
2 Te tellurium
3 O2 oxygen
4 Ni2O8Te3 nickel tellurite (Ni2Te3O8)
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 4
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Transpiration method
  • 69
  • POMD
  • 4
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Calculated from knudsen effusion weight loss
  • 3
  • RXND
  • 1
  • 4
  • 2
  • 3
  • Molar enthalpy of reaction, kJ/mol
  • From Knudsen method
  • 1