Magnetic and thermoelectric properties of electron doped Ca0.85Pr0.15MnO3

• Magnetic and thermoelectric properties have been investigated in Ca0.85Pr0.15MnO3.
• It shows a PM–AFM second order phase transition at TN=122 K.
• PM state involves modified Curie–Weiss paramagnetism.
• The electron–magnon scattering dominates temperature dependent thermoelectric power.

We have investigated temperature-dependent magnetization (M), magnetic susceptibility (χ) and thermoelectric (S) properties of the electron-doped Ca0.85Pr0.15MnO3. With decrease of temperature, paramagnetic (PM) to antiferromagnetic (AFM) phase transition occurs with a well-defined Néel temperature (TN=122 K). Magnetic susceptibility measurements reveal that the paramagnetic state involves modified Curie–Weiss paramagnetism. Field cooled and zero field cooled magnetization measurements indicate a signature of magnetic frustration. Ferromagnetic (FM) double-exchange interactions associated with doped eg electrons are favored over competing AFM interactions below Tirr=112 K. Magnetization data also shows a second-order phase transition. The sign reversal in S(T) has been interpreted in terms of the change in the electronic structure relating to the orbital degrees of freedom of the doped eg electron. Low temperature (5–140 K) thermoelectric power, S (T) signifies the importance of electron–magnon scattering process.