Title :

Ordering state in orthopyroxene as determined by precession electron diffraction

Author(s) :

Jacob, Damien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Palatinus, Lukáš [Auteur]
Institute of Physics of the Czech Academy of Sciences [FZU / CAS]
Cuvillier, Priscille [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Leroux, Hugues [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Domeneghetti, Chiara [Auteur]
Dipartimento di Scienze della Terra e dell'Ambiente [Pavia]
Cámara, Fernando [Auteur]
Dipartimento di Scienze della Terra "Ardito Desio"

Journal title :

American Mineralogist

Volume number :

98

Pages :

1526-1534

Publication date :

2013

HAL domain(s) :

Planète et Univers [physics]/Astrophysique [astro-ph]
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Sciences de la Terre
Chimie/Matériaux
Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]

English abstract : [en]

Fe2+ and Mg distribution on octahedral M1 and M2 sites of the orthopyroxene structure is an indicator of the cooling rate and closure temperature of the mineral. It is generally obtained by single-crystal X-ray diffraction, ...
Show more >Fe2+ and Mg distribution on octahedral M1 and M2 sites of the orthopyroxene structure is an indicator of the cooling rate and closure temperature of the mineral. It is generally obtained by single-crystal X-ray diffraction, which is limited in spatial resolution. In this work, we determine the cationic distribution at a submicrometer scale in a transmission electron microscope using precession electron diffraction. Two orthopyroxene samples coming from the same metamorphic rock are studied, a naturally ordered one and a disordered one. The latter was obtained from the ordered sample by annealing at high temperature and rapid quenching. Both samples have been first studied in X-ray diffraction and then in precession electron diffraction. Intensities recorded in zone-axis precession electron diffraction experiments have been quantitatively analyzed and compared to simulations, taking into account dynamical interactions between diffracted beams. Our structure refinement results are in good agreement with those obtained by single-crystal X-ray diffraction. They enable to distinguish between the ordered sample and the disordered one in terms of the observed molar fractions of Fe at M1 and M2 sites. We discuss the sensitivity of the method as a function of experimental parameters. The larger dispersion of the results obtained on the ordered specimen is attributed to structural heterogeneities inherent to the sample.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
ENSCL
CNRS
INRA

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2019-06-03T08:52:36Z
2021-02-19T16:34:01Z