Low temperature sintering ability and electrical conductivity of SOFC interconnect material La_0.7Ca_0.3Cr_0.97O₃

Relatively low temperature (1150-1300 °C) sintering characteristics and electric conductivities of La_0.7Ca_0.3Cr_0.97O₃ with a slight Cr deficiency of 0.03, prepared by an auto-ignition process, have been discussed. The material could reach 94.3% relative density at 1200 °C for 5 h in air, which is about 200 °C lower than that of with no Cr deficiency. XRD results indicated that pure perovskite phase was formed after sintered at the temperature range of 1150-1300 °C. The sample sintered at 1250 °C had the maximum conductivity of 62.0 S cm^-1 at 850 °C in air, which is about 2.6 times as high as that of La_0.7Ca_0.3CrO₃ with no Cr deficiency. In pure H₂, it got the maximum electrical conductivity of 3.3 S cm^-1 at 850 °C as sintered at 1200 °C. The TEC of the material was about 11.4 × 10^-6 K^-1, which is very compatible to that of other common used SOFC components. Therefore, it is a simple and cost-effective interconnect material for SOFCs.