SOME PROPERTIES OF STRONTIUM-DOPED LANTHANUM CHROMITE

The properties of strontium-doped lanthanum chromite (La 0·84Sr0·16CrO3) are discussed, with particular attention to its application as an electrode material for MHD power generation. The influence of firing temperature on the ceramic properties and the behaviour of strontium carbonate as a sintering agent are described. The thermal conductivity is 5·1 w m-1 degk-1 between 1100 and 2000°k, and the thermal expansion 9·0×10-6 degk-1 averaged between 300 and 1100°k. Thermal shock resistance is fair and chemical stability is very good. The incorporation of strontium is found to reduce markedly the volatility in oxidizing atmospheres compared with that for pure lanthanum chromite. The electrical properties of both pure and strontium-doped lanthanum chromite are described, and for doped material a mobility deduced of 5×10-7 m2 v-1 s -1 at 300°k and 3×10-6 m2 v -1 s-1 at 1400°k. The electrical results are tentatively discussed using the formalism of Goodenough.