Thermodynamic Characteristics of Cobaltite(Nickelite)-Cuprate-Manganites LaSrCoCuMnO6 and LaSrNiCuMnO6

摘要

The temperature dependences of the specific heat of nanoscale (nanocluster) cobaltite(nickelite)-cuprate-manganites LaSrCoCuMnO6 and LaSrNiCuMnO6 have been studied via experimental dynamic calorimetry in the range of 298.15-673 K. The temperature dependences of the specific heat C-p(circle) similar to f(T) of LaSrCoCuMnO6 (at 323 and 523 K) and LaSrNiCuMnO6 (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-p(circle)( T) and the calculated value of entropy S-circle(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.