Daniel Chateigner | Université de Caen Normandie (original) (raw)
Uploads
Papers by Daniel Chateigner
Acta Crystallographica Section A Foundations and Advances, 2015
Reflets de la physique, 2015
The 11-years old methodology called Combined Analysis using rays (x-rays, neutrons, electrons) ha... more The 11-years old methodology called Combined Analysis using rays (x-rays, neutrons, electrons) has proved its efficiency in particular in treating QTA from diffraction spectra using x-rays, neutrons and electrons. Its success concerning QTA summarises as three main points: - it avoids tricky data reductions and corrections, that depend on more or less uncontrolled parameters, these latter becoming fitted parameters that are then better estimated - it solves the difficult overlapping peaks problem (intra- and interphases), with the use of an extended Rietveld approach - it includes the determination of other important quantities, like residual stresses, crystal sizes and microstrains, structures ... Not only Combined Analysis avoids false minima in the refinements when e.g. texture or structure is the only targeted aspect, but it also allows to benefit from anisotropies in real samples rather than to suffer for them during characterizations. We will show that Combined Analysis can be...
Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms
L'oxyde thermoélectrique (TE) Ca3Co4O9 est destiné aux applications de conversion d'énerg... more L'oxyde thermoélectrique (TE) Ca3Co4O9 est destiné aux applications de conversion d'énergie en raison de ses bonnes propriétés TE, ses stabilités chimique et thermique à l'air à haute température et la non-toxicité de ses éléments. Trois procédés de consolidation (frittage conventionnel-CS, pressage à chaud-HP et frittage flash-SPS) ont été utilisés pour élaborer des céramiques aux caractéristiques TE et fiabilité optimisées pour intégrer des dispositifs. Les conditions optimales du HP ont permis d'élaborer des matériaux denses (96%) et fortement texturés, avec une croissance notable des grains dans les plans (a,b). Leur résistivité rab est faible et donc le facteur de puissance PFab remarquable (595 µWm-1K- 2 à 900 K). Les caractéristiques mécaniques sont bien meilleures comparées au CS. Des céramiques plus denses (99.6 %) élaborées dans des temps très courts par SPS ont une faible texture. PFab est plus faible comparé au HP, mais les propriétés mécaniques sont plus...
International audienceNew compositions of refractory materials with a very high content of zircon... more International audienceNew compositions of refractory materials with a very high content of zirconia are being developed for the processing of special glasses. The use of these refractories requires good control of the manufacturing process to avoid critical flaws due to severe thermo-mechanical stresses. These materials exhibit a microstructure containing monoclinic zirconia dendrites embedded into a glassy phase. The purpose of this study is to characterize the coupling between the microstructural texture and the cooling process of high zirconia refractories. The cooling stage creates an important thermal gradient between the core and the skin of the block. During this cooling process, zirconia crystallizes under the cubic (C) phase and then two phase transitions occur (cubic to tetragonal (T) and tetragonal to monoclinic (M)), which can influence the macroscopic mechanical properties. Neutron diffraction experiments have been performed, on samples from solidified blocks to evaluate the relationship between the thermal gradient of cooling and the crystallographic texture. It was shown that the stress field created during the cooling process manages the preferential orientation of zirconia crystals
Physical Review Letters, 1997
Physica C: Superconductivity, 1995
Journal of Magnetism and Magnetic Materials, 1992
... Alternatively, the whole collection of the COD files and database tables can be downloaded fr... more ... Alternatively, the whole collection of the COD files and database tables can be downloaded from the COD web site ... The open-access nature of the COD and the PCOD permits the creation of numerous mirrors of the COD and ... Future directions of COD and PCOD development. ...
Acta Crystallographica Section A Foundations and Advances, 2015
Reflets de la physique, 2015
The 11-years old methodology called Combined Analysis using rays (x-rays, neutrons, electrons) ha... more The 11-years old methodology called Combined Analysis using rays (x-rays, neutrons, electrons) has proved its efficiency in particular in treating QTA from diffraction spectra using x-rays, neutrons and electrons. Its success concerning QTA summarises as three main points: - it avoids tricky data reductions and corrections, that depend on more or less uncontrolled parameters, these latter becoming fitted parameters that are then better estimated - it solves the difficult overlapping peaks problem (intra- and interphases), with the use of an extended Rietveld approach - it includes the determination of other important quantities, like residual stresses, crystal sizes and microstrains, structures ... Not only Combined Analysis avoids false minima in the refinements when e.g. texture or structure is the only targeted aspect, but it also allows to benefit from anisotropies in real samples rather than to suffer for them during characterizations. We will show that Combined Analysis can be...
Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms
L'oxyde thermoélectrique (TE) Ca3Co4O9 est destiné aux applications de conversion d'énerg... more L'oxyde thermoélectrique (TE) Ca3Co4O9 est destiné aux applications de conversion d'énergie en raison de ses bonnes propriétés TE, ses stabilités chimique et thermique à l'air à haute température et la non-toxicité de ses éléments. Trois procédés de consolidation (frittage conventionnel-CS, pressage à chaud-HP et frittage flash-SPS) ont été utilisés pour élaborer des céramiques aux caractéristiques TE et fiabilité optimisées pour intégrer des dispositifs. Les conditions optimales du HP ont permis d'élaborer des matériaux denses (96%) et fortement texturés, avec une croissance notable des grains dans les plans (a,b). Leur résistivité rab est faible et donc le facteur de puissance PFab remarquable (595 µWm-1K- 2 à 900 K). Les caractéristiques mécaniques sont bien meilleures comparées au CS. Des céramiques plus denses (99.6 %) élaborées dans des temps très courts par SPS ont une faible texture. PFab est plus faible comparé au HP, mais les propriétés mécaniques sont plus...
International audienceNew compositions of refractory materials with a very high content of zircon... more International audienceNew compositions of refractory materials with a very high content of zirconia are being developed for the processing of special glasses. The use of these refractories requires good control of the manufacturing process to avoid critical flaws due to severe thermo-mechanical stresses. These materials exhibit a microstructure containing monoclinic zirconia dendrites embedded into a glassy phase. The purpose of this study is to characterize the coupling between the microstructural texture and the cooling process of high zirconia refractories. The cooling stage creates an important thermal gradient between the core and the skin of the block. During this cooling process, zirconia crystallizes under the cubic (C) phase and then two phase transitions occur (cubic to tetragonal (T) and tetragonal to monoclinic (M)), which can influence the macroscopic mechanical properties. Neutron diffraction experiments have been performed, on samples from solidified blocks to evaluate the relationship between the thermal gradient of cooling and the crystallographic texture. It was shown that the stress field created during the cooling process manages the preferential orientation of zirconia crystals
Physical Review Letters, 1997
Physica C: Superconductivity, 1995
Journal of Magnetism and Magnetic Materials, 1992
... Alternatively, the whole collection of the COD files and database tables can be downloaded fr... more ... Alternatively, the whole collection of the COD files and database tables can be downloaded from the COD web site ... The open-access nature of the COD and the PCOD permits the creation of numerous mirrors of the COD and ... Future directions of COD and PCOD development. ...