Thermodynamical properties of (Pr1−ySmy)0.7Ca0.3CoO3 (0 ≤ y ≤ 1)

The thermodynamical and allied properties of (Pr1−ySmy)0.7Ca0.3CoO3 (0 ≤ y ≤ 1) were investigated in this paper by means of a modified rigid ion model (MRIM) with pair wise interatomic interaction potential. The calculated specific heat, bulk modulus, and other thermal properties reproduce well with the available experimental data, implying that MRIM represents properly the nature of the perovskite type cobaltates. The specific heats are found to increase with temperature and decrease with concentration (y) for the present cobaltates. The increase in Debye temperature (θD) indicates an anomalous softening of the lattice specific heat due to increase in T3-term in the specific heat occurs with the decrease of y.

Computed specific heat of (Pr1−ySmy)0.7Ca0.3CoO3 (0 ≤ y ≤ 1) for the temperature range 1 K ≤ T ≤ 300 K. The curves of higher doping are shifted upward by 10 J each from the preceding curve for clarity.Figure optionsDownload as PowerPoint slideHighlights
► The negative values of cohesive energy show the stability of (Pr1−ySmy)0.7Ca0.3CoO3 (0 ≤ y ≤ 1) compounds.
► Our results on specific heat are in good agreement with the experimental data.
► The stability of (Pr1−ySmy)0.7Ca0.3CoO3 (0 ≤ y ≤ 1) perovskite increases with the Sm substitution.