DSC Spectroscopic Investigation of Nd0.5Ca0.5MnO3, Pr0.5Ca0.5MnO3, and Nd0.5Sr0.5MnO3 Compounds

In this work, the thermal properties of perovskite-type manganite compounds—Nd0.5Ca0.5MnO3, Pr0.5Ca0.5MnO3, and Pr0.5Sr0.5MnO3—were systematically studied using Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), and Derivative Thermogravimetry (DTG) over the temperature range of 30 to 900°C. The DSC results revealed a two-stage thermal behavior in all samples: an initial increase in heat flow up to ~300°C attributed to the desorption of surface-bound impurities, followed by a nearly linear trend at higher temperatures, indicating thermal stability. Both DTA and DTG analyses showed additional features above 650°C, particularly, in Nd0.5Ca0.5MnO3, where signs of oxidative transformations and mass variations were observed. Those effects were found to be irreversible, as confirmed by the absence of corresponding features during cooling. Furthermore, the specific heat capacity measurements demonstrated nearly identical thermal behavior across all samples at lower temperatures, with material-specific divergence becoming evident above 300°C. The findings highlight significant differences in the thermal stability and reactivity among the studied compounds, providing valuable insight into their potential use in high-temperature and thermally dynamic applications.