It was recalled that cubic-structured solid electrolytes were usually doped with a single element from the lanthanide series. An investigation was made here of the effect of co-doping, with several elements, in terms of the effect upon the ionic conductivity. It was found that, for a given total dopant concentration, mixtures of dopants led to a 10 to 30% higher total ionic conductivity than did the best singly-doped material.

Lanthanide Co-Doping of Solid Electrolytes: AC Conductivity Behavior. J.Van Herle, D.Seneviratne, A.J.McEvoy: Journal of the European Ceramic Society, 1999, 19[6-7], 837-41