It was noted that up to 10at% of Li+, Zn2+, Al3+, Ti4+ or Ge4+ could be readily substituted for V in / structures. It was found that the  phases were good O-ion conductors. The Ti-substituted  phase, Bi4V1.8Ti0.2O10.9, was the best ionic conductor among the substituted vanadates which were investigated here (table 33). It was suggested that a high ionic potential of the dopant cation facilitated O-ion mobility in the disordered phase of the substituted vanadate.

V.Sharma, A.K.Shukla, J.Gopalakrishnan: Solid State Ionics, 1992, 58[3-4], 359-62