Conductivity and structure of sub-micrometric SrTiO3-YSZ composites

The consolidated composites were studied by impedance spectroscopy between 200 and 400 °C and at a fixed temperature of 600 °C with a scan in the partial pressure of oxygen. The composites did not exhibit high levels of ionic conductivity in the grain boundary nor the bulk. The conductivity of Na-free composites shows lower levels of conductivity than pure YSZ, while samples with Na showed increased conductivity. The conductivity of SrTiO3 exhibited an enhancement attributed to p-type conductivity, although contributions from protons cannot be disregarded as some Na doping is present.