High-temperature infrared properties of forsterite

Autor: Patrick Echegut, Domingos De Sousa Meneses, Myriam Eckes, Benoit Gibert, Mohammed Malki
Přispěvatelé: Géosciences Montpellier, Université des Antilles et de la Guyane (UAG)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Physics and Chemistry of Minerals
Physics and Chemistry of Minerals, Springer Verlag, 2013, 40 (4), pp.287-298. ⟨10.1007/s00269-013-0570-z⟩
ISSN: 0342-1791
1432-2021
DOI: 10.1007/s00269-013-0570-z⟩
Popis: International audience; Polarized emittance measurements were acquired for synthetic forsterite, the pure magnesium end member of the olivines group, on the whole infrared spectral range and up to the melting point by using CO2 laser heating. The experimental data, fitted with a semi-quantum dielectric function model, allowed the retrieval of the temperature dependence of the absorption coefficient of forsterite both in the opaque and semi-transparent regions. The analysis of the phonon parameters indicates that the lattice dynamics evolve drastically with increasing temperature. The normal modes involving motions of the magnesium cations located in site 1 are the more impacted, and some of them vanish around 1,200 K. The results confirm that the enhancement of the lattice anharmonicity and the increasing mobility of the magnesium cations are closely linked and are at the origin of the anomalies observed in the evolution of the thermophysical properties. This complete set of spectroscopic data may be a step toward a more precise evaluation of the impact of thermal radiation heat transfer inside systems involving forsterite and quantification of their heat budget.
Databáze: OpenAIRE
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