%0 Journal Article
%A Alía, J.M.
%A Díaz de Mera, Y.
%A Edwards, H.G.M.
%A González Martín, Paloma
%A López De Andrés, María Sol
%T FT-Raman and infrared spectroscopic study ofaragonite-strontianite (CaxSr1-xC03) solid solution
%D 1997
%@ 1386-1425
%U https://hdl.handle.net/20.500.14352/56783
%X Synthetic aragonite-strontianite solid-solution samples have been studied using dispersive IR and FT-Ramanspectroscopy. In addition to the end-members, nine samples over a range of composition from Ca0,9Sr0,1CO3 toCa0,1Sr0,9CO3 were analysed. Carbonate anion internal modes are examined in detail by means of band-shape analysisand component fitting procedures. Positional disorder induced by the random cationic substitution results in strongincrease of the halfwidth in several vibrational bands. Results obtained for the doubly degenerate modes (antisymmetricstretching and bending, v3 and v4) reveal the presence of three components both in the IR antisymmetric stretchingband as well as in the Raman antisymmetric bending band. These observations are interpreted in terms of an overtone2v4 in possible Fermi resonance with the corresponding vg fundamental in the IR spectra, and the presence ofDavidov (factor group) splitting in the FT-Raman v4 band. Lattice modes in the FT-Raman spectra demonstrateweaker cohesion between the cation/carbonate/cation layers in aragonite (synth) than in strontianite (synth).
%~