Thermodynamic characteristics of cobaltite(nickelite)-cuprate-manganites $\rm LaSrCoCuMnO_6$ and $\rm LaSrNiCuMnO_6$

The temperature dependences of the specific heat of nanoscale (nanocluster) cobaltite(nickelite)-cuprate-manganites $\rm LaSrCoCuMnO_6$ and $\rm LaSrNiCuMnO_6$ have been studied via experimental dynamic calorimetry in the range of $298.15$–$673$ K. The temperature dependences of the specific heat $C^{\circ}_p \sim f(T)$ of $\rm LaSrCoCuMnO_6\,($at $323$ and $523$ K$)$ and $\rm LaSrNiCuMnO_6\,($at $348$ K$)$ exhibit anomalous jumps in the specific heat, which are likely due to the second-order phase transitions. Based on the experimental data on $C^{\circ}_(T)$ and the calculated value of entropy $S^{\circ}(298.15)$, the temperature dependences of the specific heat and thermodynamic functions of the studied compounds are calculated in the temperature range of $298.15$–$673$ K.