The influence of barium doping on the oxygen-ion diffusion and phase transition in the La2Mo2-yWyO9-δ (y=0, 1.0) oxide-ion conductors has been systematically investigated via dielectric techniques. In the Ba-doped La2Mo2O9 samples there are only two dielectric relaxation peaks Pd1 and Pd2, which are associated with the short-distance diffusion of oxygen vacancies. But in the Ba-doped La2MoWO9 members, three peaks are detected, including peak Pd1, Pd2, and peak Ph. The last is associated with the phase transition process from the static disordered state to the dynamic disordered state of oxygen ion/vacancy distribution.
Dynamics in Bi(iii)-containing apatite-type oxide ion conductors: a combined computational and experimental study