Optimization of Paris–Edinburgh press cell assemblies for in situ monochromatic X-ray diffraction and X-ray absorption

Abstract

We describe some important improvements allowed by the development of new cell assemblies coupled to opposed conical sintered diamond anvils in the Paris–Edinburgh press. We provide X-ray absorption and diffraction experiments carried out at pressures up to 16.5 GPa. The maximum temperature reached was 1800 K for P<10 GPa and 1300 K for higher pressures. The sintered diamond anvils are X-ray transparent and give access to a much larger X-ray window than the tungsten carbide anvils, even at the highest pressure. Therefore, X-ray measurements are performed using in situ cross-calibration simultaneously. We also describe a new heating setup used to reach high temperatures, despite the low conductivity of the sintered diamond core by deviating the electrical current using copper strips. These improvements are illustrated by recent data collected using angle dispersive in situ X-ray diffraction on liquid Fe-18%wt S and using EXAFS at the barium K-edge on Ba₈Si₄₆ silicon clathrates and at the iodine K-edge on iodine-intercalated nanotubes.

Keywords:

• Paris-Edinburgh press
• Sintered diamond
• High temperature

Acknowledgements

We would like to thank Dr. T. Kume (University of Gifu, Japan) for his assistance for the EXAFS experiments on clathrates and Dr. N. Bendiab (LPMCN, Lyon) and L. Alvarez (LCVN, Montpellier) for their assistance on the experiments on carbon nanotubes. We would also like to thank J.L. Sauvajol, R. Aznar and R. Almeirac (LCVN, Montpellier) for the preparation of iodine-intercalated nanotubes. H. Feret (LPMCN, Lyon) is thanked for technical help. This work was supported by the French Ministère Délégué à la Recherche et aux Nouvelles Technologies and the CNRS through grants ‘ACI-2003 n. NR0122’ and ‘ACI-2003 n. JC2077’, as well as by Université Claude Bernard Lyon 1 grant ‘BQR-2003’, the ‘Mission Ressources et Compétences Technologiques’ and the ‘Réseau technologique des Hautes Pressions’ both from the French CNRS. We also would like to thank the ESRF staff of the EXAFS beamline BM29 (S. Pasternak) and of the High Pressure Beamline ID27 (S. Bauchau and W. Crichton). The ex situ developments have been carried out at the ESRF, Grenoble, and at the LPMCN, Lyon.