A room-temperature 27Al nuclear magnetic resonance investigation was made of Pb1−xAlxF2+x (x = 0 to 0.12) solid solutions and of the ordered phase, Pb9Al2F24. Two different types of Al ion were identified, and their ratio was determined as a function of x. On the basis of 19F and 27Al nuclear magnetic resonance investigations, it was suggested that a clustering process, which involved the formation of column clusters, became increasingly extensive as x increased.

Short-Range Order and F− Ion Diffusion in the Pb1−xAlxF2+x Solid Solution II - 27Al NMR Investigation and Proposal of Clustering Process. M.El Omari, J.Senegas, J.M.Reau: Solid State Ionics, 1997, 100[3-4], 241-6