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

Abstract We have investigated temperature-dependent magnetization ( M ), magnetic susceptibility ( χ ) and thermoelectric ( S ) properties of the electron-doped Ca 0.85 Pr 0.15 MnO 3 . With decrease of temperature, paramagnetic (PM) to antiferromagnetic (AFM) phase transition occurs with a well-defined Neel temperature ( T N =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 e g electrons are favored over competing AFM interactions below T irr =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 e g electron. Low temperature (5–140 K) thermoelectric power, S ( T ) signifies the importance of electron–magnon scattering process.