Skip to Main content Skip to Navigation
Theses

Opacification de matériaux oxydes au passage solide-liquide : rôle de la structure et de la dynamique

Abstract : With increasing temperature, some oxide compounds that are transparent in the near infrared range become progressively opaque when approaching the liquid phase. Such a behavior is unusual and deeply impacts their thermal radiative properties. To understand this phenomenon, infrared emittance spectra were acquired from room temperature up to the liquid state on several crystalline oxides (Mg2SiO4, LiAlO2, LiGaO2, ZnO, YAlO3, LaAlO3, LiNbO3, MgO). These data have been selectively completed by electrical conductivity measurements, NMR and X-ray diffraction experiments versus temperature. The analysis of the experimental emittance data with a semi-quantum dielectric function model including an extended Drude term, allowed to characterize finely the material responses and to suggest a physical origin for the opacification mechanism. The phenomenon is thermally activated and can be explained by the formation and the mobility of polarons. This work also showed the existence of a close link between the material microstructure and the characteristics of the opacification.
Document type :
Theses
Complete list of metadatas

Cited literature [61 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00838948
Contributor : Abes Star :  Contact
Submitted on : Friday, August 29, 2014 - 4:09:34 PM
Last modification on : Thursday, March 5, 2020 - 6:49:34 PM
Long-term archiving on: : Sunday, November 30, 2014 - 11:15:45 AM

File

myriam.eckes_2632.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00838948, version 1

Collections

Citation

Myriam Eckes. Opacification de matériaux oxydes au passage solide-liquide : rôle de la structure et de la dynamique. Autre. Université d'Orléans, 2012. Français. ⟨NNT : 2012ORLE2060⟩. ⟨tel-00838948⟩

Share

Metrics

Record views

421

Files downloads

696