By combining structural and electrical data on nano-structured Li-doped material, the relationship between crystal structure and Li+-ion conductivity was derived. A maximum in the ionic conductivity was located by changing the Li-doping level, and was related to structural changes. Two existing defect models for this material had been based upon structural factors, but the present maximum in conductivity could not be explained by these models. Preliminary Rietveld-refined X-ray diffraction data suggested that the maximum could be attributed to a change in the a- and c-axes, and the related tunnel size for Li+ ions. Another possible explanation for the conductivity maximum was an effect of the particle size; which depended upon the Li-doping level.

Li+-Ion Conductivity of BPO4-Li2O; the Relation between Crystal Structure and Ionic Conductivity. M.J.G.Jak, E.M.Kelder, Z.A.Kaszkur, J.Pielaszek, J.Schoonman: Solid State Ionics, 1999, 119[1-4], 159-64