Temperature dependence of the specific heat of Pr1-xTbxCoO3(0 ≤ x ≤ 1)

In the present work, the specific heat of the perovskite-type rare earth cobalt oxide Pr1-xTbxCoO3(0 ≤ x ≤ 1) has been investigated for the first time using extended rigid ion model (ERIM) after improving modified rigid ion model (MRIM) developed recently by some of us and applied successfully on pure and doped perovskite manganites and multiferroic materials. The interatomic potential has been applied to study the specific heat as a function of temperature. The trends of variation of our computed specific heats with temperature are in agreement with corresponding experimental data by H. Hashimoto et al. for almost all the compositions (x) of Pr1-xTbxCoO3 with minor deviations at higher temperatures. The system exhibits cubic phase for x = 0 and 0.25 while orthorhombic phase above 0.5, results in the distortion of CoO6 octahedron. The existence of the peaks in specific heat results suggested that these compounds undergo metal-insulator transition. The specific heats are found to increase with temperature. The values of specific heats also increase with composition (x) when we go from x = 0.0 to 1.0 in these perovskites. These features are exhibited by both the experimental and our theoretical results. In addition, we have used extended rigid ion model (ERIM) developed from the interatomic potential to compute the thermodynamical parameters whose results are discussed in detail for the present system of cobalt oxides. (author)