Pressure calibration in high pressure EXAFS experiments

Abstract

To avoid glitches due to Bragg reflection we use boron carbide anvils for our high pressure EXAFS experiments. Since boron carbide precludes the ruby fluorescence pressure calibration we use the EXAFS of selected materials to measure the reduction with pressure of the nearest neighbor distance and infer the pressure from an isothermal equation of state. The requirements for a good pressure calibrant and the difficulties in EXAFS data analysis are discussed. Cu, NaBr and RbCl have successfully been tested as pressure calibrants.