Thermal, Thermodynamic, and Magnetic Properties of Europium Stannate Eu2Sn2O7

• Published in: Russian journal of inorganic chemistry 2022-11, Vol.67 (11), p.1803-1812
• Main Authors: Gagarin, P. G., Gus’kov, A. V., Gus’kov, V. N., Kondrat’eva, O. N., Nikiforova, G. E., Pechkovskaya, K. I., Ryumin, M. A., Tyurin, A. V., Khoroshilov, A. V., Efimov, N. N., Gavrichev, K. S.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Enthalpy; Europium; High temperature; Inorganic Chemistry; Magnetic properties; Phase transitions; Physical Methods of Investigation; Specific heat; Temperature dependence; Thermal expansion; Unit cell
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023622601015

The heat capacity of europium stannate with the pyrochlore structure was measured in the temperature range 3–1350 K using relaxation, adiabatic, and differential scanning calorimetry. The entropy, enthalpy change, and derived Gibbs energy of Eu 2 Sn 2 O 7 were calculated from the fitted heat capacity data. The temperature-dependent excess heat capacity related to Schottky’s anomaly was described in terms of the Westrum model. The Gibbs energies of formation Δ f G °(Eu 2 Sn 2 O 7 ) from elements and from constituent binary oxides were estimated from literature data and the values obtained in this work. An analysis of the magnetic properties of europium stannate showed the absence of magnetic phase transitions in the temperature range from 2 to 300 K. Thermal expansion coefficients were calculated from the unit cell parameters measured by high-temperature X-ray diffraction experiments in the range 300–1273 K.