On the ionic conductivity of some zirconia-derived high-entropy oxides

The reported High Entropy Oxides (HEOs) up to now exhibit lower ionic conductivity values than those of classical SOFC electrolytes. Multi-cations oxides, stabilized with the fluorite-type structure are investigated here in order examine whether high entropy is relevant enhance anionic such HEOs, or not. two synthesis routes that used do not show significant impact on material properties. Based configurational (? 1.5 kB/f.u. for HEOs) and radius difference calculations, new compositions designed prepared: i) (Hf1/3Ce1/3Zr1/3)1-x(Gd1/2Y1/2)xO2-x/2 series which x ratio increased so as promote a vacancy concentration, ii) (HfxCeyZr1-x-y)0.85Yb0.15O1.93 based critical concept. these HEOs slightly improved compared previously data but does exceed 4 × 10?4 S.cm?1 at 600 °C. Possible causes low value discussed.