Synthesis of single phase Ce doped nanocrystalline LaMnO3

It has been reported that the electron (Ce) doped LaMnO3 compounds are multi-phased when prepared through solid state reaction and precipitation method. However, the laser ablated thin films of the above show single phase nature. Here, we report the synthesis of single phase nanocrystalline La0.85Ce0.15MnO3 and La0.8Ce0.2MnO3 powders through citrate-complex method. In this method, the metal ions are homogeneously dispersed in amorphous organic (citrate) complex and are allowed to react while calcination. Thus, the reacted metal ions give single phase compounds. The measured average particle size from transmission electron micrograph is found to be 30nm for La0.8Ce0.2MnO3 sample. Temperature dependence of magnetization of both the samples show ferro- to paramagnetic transition and zero field cooled and field cooled magnetization curves suggest cluster glass behaviour. Temperature dependence of resistance of the La0.8Ce0.2MnO3 sample exhibits a metal to insulator transition at 110K and shows no impurity peak around 250K, which is generally observed in multi-phase samples. Magnetoresistance decreases with increasing temperature in ferromagnetic regime, as observed in typical hole doped nanocrystalline manganites.