Étude des propriétés électriques de

Conductivity of perovskite-type oxide LSM20 was measured in air for different temperatures (375-1273 ◦ K) using the 4 point method. LSM20 was prepared by solid-state reaction starting from mixtures of La2O3, MnCO3, and SrCO3 and sintered at 1673 ◦ K. The results show that conductivity obeys the following law: σ = AT 3/2 exp (−(Ea/kT )), which is representative of an activated jump mechanism between Mn 3+ and Mn 4+ sites. The LSM20- n(nanometric)YZ8 interface was characterized by impedance spectroscopy. Symmetrical cells with two LSM20 electrodes were used. The electrolyte conductivity values are very close to those obtained with silver electrodes (Ag-nYZ8) showing that the electrolyte response is independent of the nature of the electrode material. The study of the electrode conductivity versus temperature shows an activation energy equal to 1.67 eV slightly lower than that