Synthesis and properties of (La_0.75Sr_0.25)_0.95MnO_3±δ nano-powder prepared via Pechini route

(La_0.75Sr_0.25)_0.95MnO_3±δ (LSM) powders have been synthesized via a Pechini route. The prepared powders were characterized by XRD, SEM, XRF, BET and particle size distribution (PSD) analysis. It is shown that the morphology and structure of the oxide particles are significantly dependent on the preparation conditions such as the sort of surfactant and pH value of the starting solution. High purity, single phase, homogeneous, nanocrystalline LSM powders with slight aggregation were obtained using citric acid as complexing agent, ethylene glycol as surfactant and pH 1. The conductivity of the sintered LSM sample prepared from this nanocrystalline powders was mensurated about 200 S cm^-1 in air at 600-1000 °C. The impedance spectra of symmetric cells LSM-YSZ/YSZ/LSM-YSZ were measured in air and open circuit voltage condition. The optimal polarization resistance (R_p) of 0.175 Ω cm² at 750 °C and 0.07 Ω cm² at 800 °C was obtained in the sample with LSM to YSZ weight ratio of 49:51.