Affiliation:
1. National Research Lobachevsky State University of Nizhny Novgorod
2. National Research Ogarev Mordovia State University
Abstract
This paper presents the results of a study of the KFe0.33W1.67O6 system. The compound was obtained by a solid-phase synthesis method at a temperature of 1073 K. The structural, morphological, and spectroscopic properties of KFe0.33W1.67O6 were characterized using XRD, SEM-EDS. The compound crystallizes in a cubic lattice with the space group Fd–3m (227). The obtained lattice parameter a = 10.3697 (3) Å. The phase transitions of KFe0.33W1.67O6 were determined by low-temperature and high-temperature X-ray diffraction. The temperature dependence of heat capacity of KFe0.33W1.67O6 has been measured for the first time in the range from 5 to 638 K by precision adiabatic vacuum calorimetry and differential scanning calorimetry. The experimental data were used to calculate standard thermodynamic functions, namely the heat capacity C∘p∘(T), enthalpy H°(T) − H°(0), entropy S°(T) − S°(0), and Gibbs function G°(T) − H°(0), for the range from T → 0 to 630 K.
Publisher
The Russian Academy of Sciences
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