Using uranium to create order from disorder

The first demonstration of reversible symmetry lowering phase transformation with heating.

ANSTO’s unique landmark infrastructure has been used to study uranium, the keystone to the nuclear fuel cycle. The advanced instruments at the Australian Synchrotron and the Australian Centre for Neutron Scattering  have not only provided high resolution and precision, but also allowed in situ experiments to be carried out under extreme sample environments such as high temperature, high pressure and controlled gas atmosphere.

As part of his joint PhD studies at the University of Sydney and ANSTO, Gabriel Murphy has been investigating the condensed matter chemistry of a crystalline material, oxygen-deficient strontium uranium oxide, SrUO4-x, which exhibits the unusual property of having ordered defects at high temperatures.

“Strontium uranium oxide is potentially relevant to spent nuclear fuel partitioning and reprocessing,” said Dr Zhaoming Zhang, Gabriel’s ANSTO supervisor and a co-author on the paper with Prof Brendan Kennedy of the University of Sydney that was published recently in Inorganic Chemistry.
Uranium oxides can access several valence states, from tetravalent— encountered commonly in UO2 nuclear fuels, to pentavalent and hexavalent—encountered in both fuel precursor preparation and fuel reprocessing conditions.
Pertinent to the latter scenario, the common fission daughter Sr-90 may react with oxidised uranium to form ternary phases such as SrUO4.

>Read more on the Australian Synchrotron website

Image: Dr Zhaoming Zhang and Gabriel Murphy.

Tripling the energy storage of lithium-ion batteries

Scientists have synthesized a new cathode material from iron fluoride that surpasses the capacity limits of traditional lithium-ion batteries.

As the demand for smartphones, electric vehicles, and renewable energy continues to rise, scientists are searching for ways to improve lithium-ion batteries—the most common type of battery found in home electronics and a promising solution for grid-scale energy storage. Increasing the energy density of lithium-ion batteries could facilitate the development of advanced technologies with long-lasting batteries, as well as the widespread use of wind and solar energy. Now, researchers have made significant progress toward achieving that goal.

A collaboration led by scientists at the University of Maryland (UMD), the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, and the U.S. Army Research Lab have developed and studied a new cathode material that could triple the energy density of lithium-ion battery electrodes. Their research was published on June 13 in Nature Communications.

>Read more on the NSLS-II at Brookhaven National Lab website

Image: Brookhaven scientists are shown at the Center for Functional Nanomaterials. Pictured from left to right are: (top row) Jianming Bai, Seongmin Bak, and Sooyeon Hwang; (bottom row) Dong Su and Enyuan Hu.

The power of Metal-Organic Frameworks

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.

>Read more on the Diamond Light Source website

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.

Prehistoric Iranian glass under synchrotron light

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