The absorption bands were caused
by the vibrations in CO3 2− at 400–1800 cm−1. The strong absorption
bands, centered at about 1449 cm−1 for SrCO3 and 1447 cm−1 for
BaCO3, are connected with the asymmetric stretching vibrations.
Strong narrow absorption bands at about 865 cm−1 and 707 cm−1
for SrCO3, and 862 cm−1 and 696 cm−1 for BaCO3 are assigned to be
out of plane bending vibrations and in plane bending vibrations,
respectively.