Effects of Ca²⁺ and Cu²⁺ doping on sintering and electrical properties of La_0.85Sr_0.15CrO₃

La_0.85Sr_0.15CrO₃ is commonly used as the ceramic interconnect material for solid oxide fuel cell (SOFC) applications. However, it is difficult to sinter this type of material to high density. The effects of Ca²⁺ and Cu²⁺ doping substitution on the sintering characteristics, thermal expansion and electrical conductivity properties of La_0.85Sr_0.15-xCa_x Cr_1-yCu_yO₃ were investigated. It was found that the electrical conductivity of La_0.85Sr_0.15CrO₃ was effectively improved at x=0.05 and y=0, a peak value of 20.1 S/cm was obtained at 800°C. The study of La and Cr co-doping found that the sintering temperature of the sample was reduced by 100°C at x=0.05 and y=0.05, while the bulk density was increased by 31.6%. Meanwhile, the thermal expansion coefficient of samples was compared with that of 8YSZ electrolyte.