Low-frequency Raman spectra of kaolinite/alkali halide complexes

The 50–1000 cm−1 region of the Raman spectra of five kaolinite/alkali halide/water intercalation complexes is reported, and compared with both the Raman spectrum of a reference kaolinite and infrared spectra of the complexes. The alkali halides were KCl, KBr, RbCl, CsCl and CsBr. Most of the 26 Raman bands observed for the complexes can be correlated with Raman and infrared frequencies in uncomplexed kaolinite, permitting assignments based on previously published data. Some of these bands shifted or intensified due to the interaction of kaolinite with water and alkali halide. New Raman bands detected in the spectra of the chloride complexes probably arise from the keying of this ion through the ditrigonal hole into the TO layer.