Thermal transport in electron-doped manganites Ca1-xCexMnO3

We have investigated thermal transport properties (Seebeck effect and thermal conductivity) of two-electron-doped manganite Ca1-xCexMnO3. The Ce4+ substitution for Ca2+ causes two-electron doping into insulating CaMnO3 without eg electron. Single phase samples of polycrystalline Cal(1-x)Ce(x)MnO(3)(x = 0,0.05,0.1 and 0.2) were prepared with a solid-state reaction method. The light doping of Cc gives rise to a clear variation in the S(T) behavior from thermally activated dependence (T-1) to T-linear-like dependences at both x = 0.03 and 0.05. The phonon thermal conduction is strongly suppressed with increasing the Ce content. We attribute this to an enhancement of Jahn-Teller (JT) local lattice distortion due to eg orbital of 3d electron. (c) 2006 Elsevier B.V. All rights reserved.