Publications des scientifiques de l'IRD

Balan Etienne, Blanchard M., Yi H. H., Ingrin J. (2013). Theoretical study of OH-defects in pure enstatite. Physics and Chemistry of Minerals, 40 (1), p. 41-50. ISSN 0342-1791.

Titre du document
Theoretical study of OH-defects in pure enstatite
Année de publication
2013
Type de document
Article référencé dans le Web of Science WOS:000313053300006
Auteurs
Balan Etienne, Blanchard M., Yi H. H., Ingrin J.
Source
Physics and Chemistry of Minerals, 2013, 40 (1), p. 41-50 ISSN 0342-1791
The infrared spectroscopic properties of selected defects in orthoenstatite are investigated by first-principles calculations. The considered defects include doubly protonated Mg vacancies at M1 and M2 sites, fully protonated SiA and SiB vacancies (hydrogarnet defects), and doubly protonated SiA and SiB vacancies associated with interstitial Mg2+ cations. The bands observed at 3,070 and 3,360 cm(-1) in the spectrum of synthetic enstatite samples are ascribed to O2A-H and O2B-H groups, respectively, associated with M2 vacancies. The theoretical models suggest that bands observed at 3,590 and 3,690 cm(-1) in the spectrum of enstatite samples synthesized under low silica-activity conditions correspond to O2H and O1H groups associated with SiB vacancies partially compensated by interstitial Mg2+ cations in fivefold coordination. The theoretical relation between the integrated absorption coefficient of OH-defects and vibrational frequencies is consistent with previous observations indicating that the absorption coefficients of OH-defects are comparatively stronger in enstatite than in the olivine polymorphs.
Plan de classement
Géologie et formations superficielles [064]
Localisation
Fonds IRD [F B010058839]
Identifiant IRD
fdi:010058839
Contact