A physicochemical study of the perovskites MII(In2/3U1/3)O3 (MII = Sr, Ba) at low temperatures

The heat capacity of crystalline Sr(In2/3U1/3)O3 and Ba(In2/3U1/3)O3 in the range 80–350 K was determined by adiabatic vacuum calorimetry, and the thermodynamic functions of these compounds in the range from T → 0 to 350 K were calculated. The standard entropies of formation of these compounds at 298.15 K were calculated. The absolute entropies and standard entropies of formation of perovskites MII(AIII 2/3U1/3)O3 (MII = Sr, AIII = Sc, In, Fe; MII = Ba, AIII = Sc, In, Y, Nd-Lu) were estimated.