Recent Developments in Static High Pressure Research

Abstract

The development of the diamond anvil cell for x-ray and spectroscopic studies has given a new impetus to high pressure static research.1) At the Geophysical Laboratory in Washington DC, pressures in excess of 2.5 megabars have been reached with the diamond cell recently, and high pressure x-ray studies in the megabar range are almost routine. In the same laboratory Raman measurements on solid hydrogen have been extended to 1.5 megabar pressure. This is the highest pressure at which any spectroscopic measurement has been performed. While these developments are at the boundaries of static high pressure range, it has now become possible to carry out x-ray and spectroscopic measurements to several hundred kilobars routinely. The interfacing of the diamond cell with synchrotron sources2) has revolutionized high pressure x-ray diffraction investigations. Compression measurements, phase transition and structural studies at high pressure are greatly facilitated by the rapidity with which high pressure x-ray diffraction data can be obtained with synchrotron sources.