Electrical transport of Ce doped La–Ca–Mn–O system

We report here the low temperature (below transition temperature TP) resistivity behavior of Ce doped La0.7Ca0.3MnO3. Polycrystalline samples of compositions La0.7Ca0.3MnO3 (sample 1), La0.7Ca0.25Ce0.05MnO3 (sample 2) and La0.65Ce0.05Ca0.3MnO3 (sample 3) were prepared by solid state route method. From the XRD studies, it is revealed that all the samples exhibit the single phase with orthorhombic structure (Space group Pnma). From the resistivity data, it is found that all the samples show metal to insulator transition and with the Ce doping the transition temperature (TP) decreases. The resistivity data in the metallic region from 55 K to 190 K show T2 dependence for all the samples, consistent with the electron–electron scattering. In the temperature range above 190 K, the two-magnon and electron–phonon processes contribute to scattering of carriers. It is also found that the value of resistivity increases with the doping of Ce on Ca site but decreases with the doping of Ce on La site.