Thermodynamic properties of Ln1−xSrxCoO3 (Ln = Pr, Nd, Sm and Dy)

• Probably the first report on the specific heat and thermal expansion in Ln1−xSrxCoO3 (Ln = Pr, Nd, Sm and Dy) perovskite.
• Effect of lattice distortions on bulk modulus and thermal properties is presented.
• Thermal properties are computed using the MRIM probably for the first time.
• The negative values of cohesive energy show the stability of these compounds.

We have investigated the thermodynamic properties of Ln1−xSrxCoO3 (Ln = Pr, Nd, Sm, Dy and 0 ≤ x ≤ 1) perovskites using modified rigid ion model (MRIM) and a novel atomistic approach of Atoms in Molecules (AIM) theory. The effect of Sr doping on lattice specific heat and thermal expansion coefficient as a function of temperature (1 K ≤ T ≤ 300 K) are reported probably for the first time. The MRIM results on thermal expansion coefficient of Sr doped LnCoO3 (Ln = Pr, Nd, Sm and Dy) suggest that higher Sr doping may not be applicable to solid oxide fuel cell. Besides, we have reported bulk modulus (B), cohesive energy (ϕ), molecular force constant (f), Reststrahlen frequency (υ), Debye temperature (θD), Gruneisen parameter (γ) and specific heat. It is found that the present model has a promise to predict the thermodynamic properties of other perovskites as well.