Low-temperature reaction of aurivillius phases with halides

Kijima et al, CT, Kijima, S, Kimura, Y, Kawahara, K, Ohe, M. Yada, and M, M achida, J, Solid State Chem, 146, 60 (1999)] recently reported a reaction b etween Bi4Ti3O12 and LiI in the presence of iodine at 350 degrees C. Their product was never obtained free of Bi4Ti3O12, but their claim was that thei r product was Bi4Ti3O12 intercalated with I and Li, We have repeated this r eaction and found conditions under which the reaction goes to completion, i .e., Bi4Ti3O12 is completely consumed, The dominant crystalline product is apparently identical to the product reported by Kijima et al. However, we c onclude that no intercalation of Bi4Ti3O12 has occurred, This dominant crys talline phase is in fact BIOI. The remainder of the product is poorly cryst alline. Analogous reactions occur at low temperature using other halides su ch as NaCl and other Aurivillius phases such as Bi2WO6. (C) 2000 Academic P ress.