Electrical and thermal properties of Sr-doped lanthanum manganites
Abstract The thermal expansion and electrical conductivity of the system (La 1− x Sr x ) 0.85 MnO 3 with a perovskite structure were studied in function of x (0.1, 0.3 and 0.5) and temperature in the RT−1000°C range. Both the conductivity and the thermal expansion linear characteristics show a change in slope in the 400–500°C range suggesting a structure transition. The dopant concentration has a large effect on these properties. The conduction mechanism changes from semi-conductor behavior to metallic one for x =0.5. The high conductivity and the very low activation energy values suggest that the conduction is mainly electronic.