抄録
The relationship between the amount of Sr substitution (x) and the physical properties of La1-xSrxMnO3, usually used for Solid Oxide Fuel Cell cathodes, was studied. Conductivity increased with an increase in the amount of Sr, and was almost constant in the range of x≥0.4. Bending strength increased in proportion to the density of the body in the range of 0.1≤x≤0.3, and decreased above that range. Thermal expansion was influenced not only by x but also by the sintering temperature. Samples sintered at 1200°C with x≤0.2 show a point of inflection caused by the phase transition at around 800°C, while samples with x≥0.3 have linear characteristics in the temperature range under 1000°C, when the sintering temperature was over 1300°C. XRD analysis showed orthorhombic structure material in the samples with 0.1≤x≤0.3 sintered at 1500°C, which have high bending strength. This material is thought to have some relationship to the increase in the bending strength of La1-xSrxMnO3. As a result, it was indicated that Sr substitution x=0.2_??_0.3 is adequate for cathode material in Solid Oxide Fuel Cells.
