FT-IR SKELETAL POWDER SPECTRA OF BA-BETA-ALUMINAS WITH COMPOSITIONS BAAL9O14.5, BAAL12O19, AND BAAL14O22 AND OF BA-FERRITE, BAFE12O19

The FT-IR/FT-FIR powder skeletal spectra of beta-aluminas of compositi on BaAl9O14.5, BaAl12O19, and BaAl14O22 and of a magnetoplumbite-type Ba-ferrite BaFe12O19 are reported and discussed, on the basis of the s tructural models previously proposed for these solids. These models fi nd good confirmation in such skeletal spectra. Emphasis is focused on the defect structure of these compounds. (C) 1995 Academic Press, Inc.