Assessment of the electronic conductivity of core-shell, Fe-doped LSGM ceramics by impedance spectroscopy

►Grain boundary engineering of mixed ionic-electronic conductors. ►Selective doping of LSGM grain boundaries with less than 1 at.% of iron. ►Grain boundary electronic conductivity is assessed by impedance spectroscopy. ►Electronic conductivity is 100-1000 times higher than undoped LSGM. ►Gains in electronic conductivity are smaller at temperatures higher than 500 °C.