Cubic Anvil X-Ray Diffraction Press Up to 100 kbar and 1000°C

Abstract

A cubic anvil X-ray diffraction press has been developed. With this apparatus powder diffraction patterns of substances subjected to quasi-hydrostatic pressure up to 100 kbar and temperature up to 1000°C can be satisfactorily obtained using a scintillation counter and an electronic counting system for detecting diffracted X-rays. To show the capabilities of this apparatus, the effect of pressure on lattice parameters of KCl, which shows NaCl type to CsCl type structural phase transformation at high pressures has been determined up to 100 kbar and thermal expansion of high pressure phase of KCl has also been measured up to 800°C. Using these data. lattice energies of both phases of KCl at the transformation pressure are calculated with the revised Born model of ionic crystals.