%0 Journal Article
%A Alía Robledo, José María
%A Edwards, H.G.M.
%A López Andrés, Sol
%A González Martín, Paloma
%A García Navarro, F.J.
%A Mansour, H.R.
%T FT-Raman study of three syntetic solid solutions formed by orthorhombic sulfates: Celestite-barytes, barytes-anglesite and celestite-anglesite
%D 2000
%@ 0038-7010
%U https://hdl.handle.net/20.500.14352/57157
%X In, the present work, three different solid solutions whose end-members arethe orthorhombic sulfates celestite (SrS04), barytes (BaS04) and anglesite (PbS04) are studied using FT-Raman spectroscopy. Sulfate anion symmetricinternal modes have been examined in detail by means of band-shape analysis andcomponent fitting procedures. The symmetric stretching mode v,(A,)changes itswavenumber position lillearly with the cationic composition of the samples whichfurther confirrns the ideal character of the solid solutions studied. The corresponding full-width at half-height is strongly increased in the centralcomponents of the different solid solutions which can be understood as an effectof the positional disorder induced by random cationic substitution. Similar resultsare observed in the syrnmetric bending mode, ~(E). The study of the lowfrequency spectral region permits one to differentiate traslational modes of thesulfate anion, which changes its wavenumberposition when the alkali-earth metal ion changes from rotational modes. This permits the tentative band assignement ofthe anglesite rotational Raman bands at 134 and 152 cm-1, which were previouslynot assigned.
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