The Raman study of certain carbonates

Abstract

Some of the most common carbonates have been investigated by non-contact Raman spectroscopy. The synthetic alkali carbonates K2CO3 and Na2CO3 have also been studied. The Raman spectrum of aurichalcite is different from that of malachite. This spectrum has a characteristic intense band at 1069 cm -1 which is assigned to the ν1 symmetric stretching mode of the carbonate unit. The two low intensity Raman lines of 1485 and 1507 cm -1 may be ascribed to the ν3 asymmetric stretching modes. To the ν4 mode (doubly degenerate symmetric bending) are attributed the values of 706 cm -1 (ν4a) and 733 cm -1 (ν4b). A number of bands with different intensities are observed in the lowest spectral shift (285, 388, 430, 461 and 498 cm -1 ). These Raman lines are assigned to the CuO and ZnO stretching and bending vibrations. A single band of the OH-stretching modes is observed at 3344 cm -1 .