Ionic conductivities of lithium fluorapatites

The electrical properties of Ca10-xMx(PO4)(6-x)(SO4)(x)F-2 apatite structur e where M = Na, Li using the complex impedance method allows us to demonstr ate the mixed ionic conduction (anionic and cationic). This effect can be a ssigned to the three-dimensional character of the diffusion process in thes e materials. The present study proves several factors are responsible for t he diffusion processes particularly the cationic site nature, the size and the polarisability of cations introduced in the system. (C) 1999 Published by Elsevier Science B.V. All rights reserved.