Surface modes in the infrared spectrum of hydrous minerals: the OH stretching modes of bayerite | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

Twitter

Aller au compte twitter

  Surface modes in the infrared spectrum of hydrous minerals: the OH stretching modes of bayerite

Type de publication:

Journal Article

Source:

Physics and Chemistry of Minerals, Volume 35, Ticket 5, p.279-285 (2008)

ISBN:

0342-1791

Numéro d'accès:

ISI:000255197200005

Mots-clés:

UMR 7154 ; Minéralogie ; N° Contribution : 2321

Résumé:

The theoretical infrared (IR) and Raman spectra of bayerite (beta-Al(OH)(3)) are computed in the density functional theory framework, using the linear response theory. The results are consistent with the occurrence of six non-equivalent OH groups in a bayerite structure with space group P2(1)/n. Similar to gibbsite, the transmission powder IR spectrum of bayerite in the region of the OH stretching bands is found to depend on the shape of particles. In particular, the broadening of the strong band observed at about 3,460 cm(-1) in the spectrum of Al hydroxides is related to the electrostatic charges occurring at the surface of the polarized dielectric particles. The experimental correlation observed between the shape of this band and morphological parameters has therefore a physical, instead of chemical, origin.

Notes:

Balan, Etienne Blanchard, Marc Hochepied, Jean-Francois Lazzeri, Michele