Thermal expansion and specific heat of Pr0.8Na 0.2MnO3 and Tb0.85Na0.15MnO 3 perovskite manganites

Abstract

Specific heat (Cp), thermal expansion (α) and bulk modulus of sodium doped Rare Earth manganites R1-xNaxMnO 3(R3+=La,Pr,Tb) has been studied by means of a Modified Rigid Ion Model (MRIM) and AIM theory. The partial replacement of rare earth cation by sodium introduces large size and charge mismatch at A-site affecting the bulk modulus and thermal properties. Lattice specific heat (Cp) of Pr0.8Na0.2MnO3 as a function of temperature (1K≤T≤350K) is found to be in agreement with the published data. The trend of variation of Debye temperature with A-site cationic radius is predicted probably for the first time for the doped rare earth manganites. © 2013 AIP Publishing LLC.