Two dielectric relaxation peaks associated with O-ion diffusion in the oxide-ion conductors La2–xBixMo2O9 (x = 0.05, 0.1, and 0.15) were studied. It was found that the activation energies of the two peaks increased with increasing Bi-doping concentration, which results from the blocking effects of the lone-pair electrons of Bi3+ ions. From the different effects of Bi doping on the two peaks, the diffusion paths of O ions corresponding to each peak were confirmed. Significantly, it was revealed that Bi doping could enhance the ionic conductivity of La2Mo2O9 at lower temperatures.

Dielectric Relaxation Studies of Bi-Doping Effects on Oxygen-Ion Diffusion in La2–xBixMo2O9 Oxide-Ion Conductors. X.P.Wang, Q.F.Fang, Z.S.Li, G.G.Zhang, Z.G.Yi: Applied Physics Letters, 2002, 81[18], 3434-6