Low-temperature heat capacity and thermodynamic properties of layered perovskite-like oxides NaNdTiO_4 and Na_2Nd_2Ti_3O_(10)

摘要

We report the results of the study of thermodynamic properties for layered perovskite-like oxides NaNdTiO_4 and Na_2Nd_2Ti_3O_(10). Isobaric heat capacity of the compounds was measured in an adiabatic calorimeter in the range of 5–340 K. Low-temperature heat capacity anomaly was observed in the heat capacity curve of Na_2Nd_2Ti_3O_(10). Standard thermodynamic properties of the oxides were evaluated from the experimental heat capacity temperature dependencies. Finally, on the basis of the experimental data obtained in this work, we tested applicability of the additivity principle for prediction of thermodynamic properties for layered compounds built of fragments of various structural types.