Thermodynamic properties of La1−xAxCoO3 (A=K, Cd, Pr and Nd)

We have calculated the thermal and allied properties of La1−xAxCoO3 (A=K, Cd, Pr, Nd and 0≤x≤1) as a function of temperature 1 K≤T≤300 K for the first time using Modified Rigid Ion Model (MRIM). The calculated bulk modulus, specific heat, thermal expansion and other thermodynamic properties obtained from MRIM have presented proper interpretation of the experimental data, for monovalent (K+), divalent (Cd2+) and trivalent (Pr3+ and Nd3+) ion-doped LaCoO3. In addition, the results on the cohesive energy (ϕ), molecular force constant (f), Reststrahlen frequency (υ), Debye temperature (θD) and Gruneisen parameter (γ) are also discussed.

Graphical abstractSubstitution to trivalent La3+ site by K+ ions increase the thermal expansion (α) whereas Cd2+, Pr3+ and Nd3+ results in decrease of α in La1−xAxCoO3− (A=K, Cd, Pr, Nd).Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Probably the first report on the specific heat and thermal expansion in La1−xAxCoO3. ► Thermal properties are computed using the MRIM probably for the first time. ► Effect of lattice distortions on bulk modulus and thermal properties is presented. ► The negative values of cohesive energy show the stability of these compounds.