Short-range order and F super(-) ion diffusion inside the Pb sub(1-x)Al sub(x)F sub(2+x) solid solution. Part II: super(27)Al NMR investigation and proposal of clustering process

A super(27)Al nuclear magnetic resonance (NMR) investigation at room temperature of the Pb sub(1-x)Al sub(x)F sub(2+x) (0 less than or equal to x less than or equal to 0.12) solid solution and of the ordered Pb sub(9)Al sub(2)F sub(24) phase is carried out. Two different types of aluminum ions are identified and their ratio is determined as a function of x. A clustering process based on the formation of column clusters, more and more extended when x increases, is proposed on the basis of results issued from the super(19)F (Part I) and super(27)Al NMR investigations.