X-ray powder diffraction – Page 2

Trapping nuclear waste at the molecular level

Nuclear power currently supplies just over 10% of the world’s electricity. However one factor hindering its wider implementation is the confinement of dangerous substances produced during the nuclear waste disposal process. One such bi-product of the disposal process is airborne radioactive iodine that, if ingested, poses a significant health risk to humans. The need for a high capacity, stable iodine store that has a minimised system volume is apparent – and this collaborative research project may have found a solution.

Researchers have successfully used ultra-stable MOFs to confine large amounts of iodine to an exceptionally dense area. A number of complementary experimental techniques, including measurements taken at Diamond Light Source and ISIS Neutron and Muon Source, were coupled with theoretical modelling to understand the interaction of iodine within the MOF pores at the molecular level.

High resolution x-ray powder diffraction (PXRD) data were collected at Diamond’s I11 beamline. The stability and evolution of the MOF pore was monitored as the iodine was loaded into the structure. Comparison of the loaded and empty samples revealed the framework not only adsorbed but retained the iodine within its structure.

Illustration: Airborne radioactive iodine is one of the bi-products of the nuclear waste disposal process. A recent study involving Diamond Light Source and ISIS Neutron and Muon Source showed how MOFs can capture and store iodine which may have implications for the future confinement of these hazardous substances.

Scientists from University of Isfahan in Iran have analysed in the ALBA Synchrotron how were made ancient Iranian glass objects that date back to 2.500 BC. These decorative glass pieces were excavated from the ziggurat of Chogha-Zanbil, a type of stepped pyramidal monument, inscribed on the UNESCO World Heritage List.

Ziggurats, the most distinct architectural feature of the Mesopotamian, are a type of massive stone structure built thousand years ago as a temple where deities lived. Nevertheless, Chogha-Zanbil, near Susa (Iran), is one of the few existent ziggurats found outside the Mesopotamian area. During ancient times Chogha-Zanbil was known as Dur Untaš, and may had been a sacred city of the Elamite Kingdom, an ancient Pre-Iranian civilization centred in the far West and Southwest of what is now modern-day Iran.

In order to determine the chemical composition of these unique samples, including one piece of ceramics and one piece of metallurgical crucible, a team of Iranian scientists came to ALBA Synchrotron to analyse them using X-Rays Powder Diffraction at the MSPD beamline. The MSPD analyses were carried out on more than 100 points on the glass objects. Synchrotron light enabled them to obtain high resolution diffraction patterns, from whose interpretation researchers have deduced the exact composition of the clay based structure as well as glassy part of the samples.

>Read more on the ALBA website

Image: The glass objects were originally used at the walls and doors of the tempel Chogha-Zanbil.
Credit: Mohammadamin Emami

Tag: X-ray powder diffraction

The power of Metal-Organic Frameworks

Trapping nuclear waste at the molecular level

Prehistoric Iranian glass under synchrotron light