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Thermodynamic properties of rubidium niobium tungsten oxide

  • Aleksandr Knyazev
  • Mirosław Mączka
  • Nataliya Kuznetsova
  • Jerzy Hanuza
  • Aleksey Markin
Article

Abstract

In the present work temperature dependence of heat capacity of rubidium niobium tungsten oxide has been measured first in the range from 7 to 395 K and then between 390 and 650 K, respectively, by precision adiabatic vacuum and dynamic calorimetry. The experimental data were used to calculate standard thermodynamic functions, namely the heat capacity \( C_{\text{p}}^{\text{o}} (T), \) enthalpy \( H^{\text{o}} ({\rm T}) - H^{\text{o}} (0) \), entropy \( S^{\text{o}} (T) - S^{\text{o}} \left( 0 \right) \), and Gibbs function \( G^{{^{\text{o}} }} ({\rm T}) - H^{{^{\text{o}} }} (0) \), for the range from T→0 to 650 K. The high-temperature X-ray diffraction and the differential scanning calorimetry were used for the determination of temperature and decomposition products of RbNbWO6.

Keywords

Adiabatic vacuum calorimetry Differential scanning calorimetry Heat capacity Rubidium niobium tungsten oxide Thermodynamic functions 

Notes

Acknowledgments

The work was performed with the financial support of NNSU’s innovation educational program within the National project “Education”.

Supplementary material

10973_2009_112_MOESM1_ESM.doc (166 kb)
Supplementary material 1 (DOC 166 kb)

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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2009

Authors and Affiliations

  • Aleksandr Knyazev
    • 1
  • Mirosław Mączka
    • 2
  • Nataliya Kuznetsova
    • 1
  • Jerzy Hanuza
    • 2
  • Aleksey Markin
    • 1
  1. 1.Nizhny Novgorod State UniversityNizhny NovgorodRussia
  2. 2.Instutite of Low Temperature and Structure ResearchPolish Academy of SciencesWroclawPoland

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