Thermodynamic properties of pyrochlore-like rare earth triple oxides CaLa2MoO7 and MgLa2MoO7

• Published in: Journal of thermal analysis and calorimetry 2017-04, Vol.128 (1), p.491-500
• Main Authors: Bissengaliyeva, Mira R., Taimassova, Shynar T., Zhakupov, Ramazan M., Gogol, Daniil B., Bekturganov, Nuraly S.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Pyrochlores; Specific heat; Temperature dependence; Thermodynamic properties; Thermodynamics
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-016-5865-0

The temperature dependence of the heat capacity of pyrochlore-like compounds CaLa 2 MoO 7 and MgLa 2 MoO 7 has been investigated over the range of 4.4–320 K by adiabatic calorimetry. The main thermodynamic functions and fractal properties of the compounds over the range of 5–320 K have been determined based on the experimental data. We have revealed the heat capacity anomaly in the sample CaLa 2 MoO 7 in the area below 10 K. Standard thermodynamic functions at T  = 298.15 K are: for CaLa 2 MoO 7 C p, m (298.15) = 222.1 ± 0.4 J mol −1 K −1 , S m (298.15) = 246.0 ± 0.8 J mol −1 K −1 , H m (298.15)− H m (0) = 39.20 ± 0.10 kJ mol −1 ; for MgLa 2 MoO 7 C p, m (298.15) = 216.6 ± 0.3 J mol −1 K −1 , S m (298.15) = 231.1 ± 0.6 J mol −1 K −1 , H m (298.15) −  H m (0) = 37.09 ± 0.08 kJ mol −1 .