Low-temperature heat capacities for EMoO4 (E=Mg, Sr, Ba) substances formed in nuclear fuel waste glasses

Koç H., Köse O., ESER E.

Progress in Nuclear Energy, vol.143, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 143
  • Publication Date: 2022
  • Doi Number: 10.1016/j.pnucene.2021.104054
  • Journal Name: Progress in Nuclear Energy
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Compendex, Environment Index, INSPEC, Pollution Abstracts, Civil Engineering Abstracts
  • Keywords: Heat capacity, Debye-Einstein functions, Nuclear waste glass, Yellow phase, 3RD LAW ENTROPY, RADIATION SHIELDING PROPERTIES, STANDARD GIBBS ENERGY, THERMODYNAMIC PROPERTIES, SOLUTION CALORIMETRY, ZNO, PHASES
  • Ankara Haci Bayram Veli University Affiliated: Yes

Abstract

© 2021Thermodynamic properties of various crystalline solids are evaluated from low-temperature heat capacity measurements, in the temperature range 0–300 K using semi-empirical models. Previous studies include fit functions with many coefficients resulting in almost perfect agreement with experimental data. The heat capacities of the end-members of the yellow phase formed in the nuclear fuel waste glasses can be fitted by simple Debye-Einstein integral formula to avoid overfitting. In this study, the heat capacities, the characteristic temperatures (θD,θE1,θE2) and the fitting parameters (m,n1 and n2) of MgMoO4, SrMoO4 and BaMoO4 were determined by fitting the Debye-Einstein integral to the experimental heat capacity. The Debye temperatures θD of MgMoO4, SrMoO4 and BaMoO4 are 546.15 K, 496.3 K and 420.6 K, respectively, and their Einstein temperatures (θE1,θE2) are (162.46, 1185.25) K, (169.41, 1040.56) K and (125.3, 958.87) K. It is shown from the results that the Debye-Einstein function used in the present study was found to be in good agreement with the experimental data.