Mixed conductivity of yttrium-doped strontium titanate under high temperature reducing conditions

摘要

Strontium titanate doped with yttrium was identified as an electronically conducting ceramic at moderately low oxygen pressures, typical of fuel cell anode atmospheres. The conductivity of Sr{sub}(1-3x/2)Y{sub}xTiO{sub}3 at x = 0.08 was found to be 63 S/cm at 800°C and 10{sup}(-19) atm oxygen pressure. The conductivity shows little dependence on P{sub}(O{sub}2) in the range 10{sup}(-14) to 10{sup}(-20) atm. Substitution of other rare earths such as La at x = 0.5 yielded a conductivity of 18 S/cm under the same conditions. The ionic conductivity of Y-SrTiO{sub}3 was determined to be 6 × 10{sup}(-3) S/cm.