Characterization of Gas-Solid Reactions using In Situ Powder X-ray Diffraction

Versatile in situ powder X-ray diffraction cells for solid–gas investigations

This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid-gas reactions in dosing or flow mode, but can also handle samples involved in solid-liquid-gas studies. The sample can be loaded into a s...

X-Ray Powder Diffraction Metrics

To compare sample data from x-ray diffraction a suitable metric is developed to evaluate the similarity (or dissimilarity) between samples and to compare it to a references. The methodology focuses on the d-lines and uses the intensity measurements indirectly in the algorithm. The resulting d-line distribution and summary statistics of the differences is used to establish whether a true differe...

Cation ordering in magnesioferrite, MgFe2O4, to 982 °C using in situ synchrotron X-ray powder diffraction

Magnesioferrite spinel, MgFe2O4, was synthesized at 900 °C from equimolar amounts of reagentgrade oxides, MgO and Fe2O3, and quenched in air. The structural behavior of magnesioferrite was determined from in situ synchrotron X-ray powder-diffraction data [ = 0.92225(4) Å] at room pressure and temperatures from 28 to 982 °C on heating and cooling. The a unit-cell parameter increases linearly on ...

Accurate determination of X-ray energies using powder diffraction

We report synchrotron energy determinations using the powder diffraction patterns of Si (640b) and LaB6 (660) standard reference powders at a number of energies between 5 and 20 keV. The fitted peak positions of all peaks recorded on image plates were used in each energy determination. Several sources of systematic error were investigated and their connection led to physically reasonable and co...

Two-dimensional X-ray powder diffraction