Accueil >
Production scientifique
(114) Production(s) de LE PARC R.
|
|
Amorphization of faujasite at high pressure: an X-ray diffraction and Raman spectroscopy study 
Auteur(s): Isambert Aude, Angot Emmanuel, Hébert Philippe, Haines Julien, Levelut C., Le Parc R., Ohishi Yasuo, Kohara Shinji, Keen David
(Article) Publié:
Journal Of Materials Chemistry, vol. 18 p.5746 - 5752 (2008)
Texte intégral en Openaccess : 
Ref HAL: hal-00341435_v1
DOI: 10.1039/b809774g
WoS: 000261745400005
Exporter : BibTex | endNote
34 Citations
Résumé: In situ X-ray diffraction and Raman spectroscopy measurements of synthetic powdered samples of faujasite 13X were carried out at high pressure using diamond anvil cells. Structural changes are detected, linked to a progressive reduction in crystallinity, before complete amorphization of the material. Three distinct compressibility regions are clearly observed, delimited by two discontinuities in the pressure dependence of the faujasite volume around 2 and 3.5 GPa. The transition from the crystal to the amorphous state is incomplete and partially reversible below pressures of between 8 and 12 GPa, depending on the pressure-transmitting medium used. This partial recovery of the initial structure, at least on a local level, could be related to the presence of hydrated sodium ions in the faujasite framework. In addition, the position of the first sharp diffraction peak in the X-ray diffraction pattern of a fully amorphous sample recovered from 24 GPa is consistent with the presence of 4-membered rings of tetrahedra and the persistence of a significant number of larger rings as compared to a dried amorphous faujasite precursor.
|
|
|
|
Temperature dependence and pressure dependence of the vibrational properties of corannulene
Auteur(s): Alvarez L., Le Parc R., Jourdain V., Dennler S., Bantignies J.-L., Sauvajol J.-L., Rose Jonathan A., Scott Lawrence T.
(Article) Publié:
Physica Status Solidi B, vol. 245 p.2261-2263 (2008)
Texte intégral en Openaccess :
Ref HAL: hal-00496491_v1
DOI: 10.1002/pssb.200879611
WoS: 000260581800086
Exporter : BibTex | endNote
4 Citations
Résumé: Herein, we report the experimental investigation of the vibrational properties of corannulene using Raman spectroscopy. The temperature dependences of the Raman spectra between 300 and 20 K reveal a very high sensitivity of the low frequency domain between 40 and 200 cm(-1) compared to the intramolecular domain. The behavior of the Raman modes of the corannulene under pressure, between 0.53 GPa and 8 GPa, is also studied. Under pressure, in the intermolecular vibrational domain (<150 cm(-1)), two transitions occur suggesting metastable intermediate stages under pressure. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
|
 |
Propriétés Vibrationnelles du Corannulène
Auteur(s): Le Parc R.
Conference: Journées du Groupe Français de Spectroscopie vibrationnelle (Toulouse, France, FR, 2008-06-25)
|
|
Etude de verres binaire SiO 2 GeO 2 sous pression
Auteur(s): Le Parc R.
Conference: Forum Hautes Pressions (Batz Sur Mer, France, FR, 2008-10-06)
|
|
|
|
Formation of a New Phase of C60 under the Combined Action of High-Pressure and X-Ray Radiation
Auteur(s): Papoular R. J., Le Parc R., Levelut C., Haines Julien, Davydov V. A., Rakhmanina A. V., Belova E. E., Chernozatonskii L. A., Allouchi H., Agafonov V.
(Article) Publié:
Fullerenes Nanotubes And Carbon Nanostructures, vol. 16 p.486-493 (2008)
Ref HAL: hal-00434427_v1
DOI: 10.1080/15363830802282425
WoS: 000259645200032
Exporter : BibTex | endNote
Résumé: In a recent work by Meletov et al., the further high-pressure photoinduced polymerization of the orthorhombic 1-D phase of C60 was demonstrated using Raman scattering. The pressure of the transition is about 0.3 GPa at 300 K. In our present work, a similar process is now established using X-ray irradiation as well as in-situ high-pressure X-ray powder diffraction in a diamond anvil cell. The transformation to a new phase through the simultaneous action of pressure and X-rays is observed between 0.2 and 1.66 GPa, in agreement with the aforementioned Raman results. A further increase in pressure leads gradually to the formation of a disordered phase.
|
|
High pressure study of amorphized and vitreous phase of mixed compounds from the quartz family
Auteur(s): Le Parc R., Champagnon Bernard, Martinet Christine, Levelut C., Haines Julien, Cambon Olivier, Cambon Martine, Ranieri Vincent
Conference: Joint 21st AIRAPT and 45th EHPRG International Conference on High Pressure Science and Technology (, FR, 2007-09-17)
|
|
|
|
Crystalline phase-transition in GaPO$_4$ under pressure
Auteur(s): Peireira Altair, Haines Julien, Le Parc R., Cambon Olivier, Levelut C.
Conference: Joint 21st AIRAPT and 45th EHPRG International Conference on High Pressure Science and Technology, (catania, IT, 2007-09-17)
|
