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

摘要

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 Ba{sub}8Si{sub}46 silicon clathrates and at the iodine K-edge on iodine-intercalated nanotubes.