Closer Look at Actinides
The prestigious journal Reports on Progress in Physics published a new study dealing with the interaction of actinides with hydrogen and the physical properties of actinide hydrides. Scientists, who collaborated on the review article, come from Matfyz, the Institute of Physics of the CAS and the University of Ostrava.
The interaction of actinides with hydrogen is important in nuclear energy and military, as even small amounts of hydrogen can lead to the disintegration of "components." However, affinity to hydride formation also has a positive side. Metallic uranium is used to store and release tritium in nuclear fusion systems. "Our interest lies primarily in understanding actinide metal hydrides and intermetallic compounds as solids combining the lightest and heaviest elements of the periodic system," says Ladislav Havela, a senior lecturer from the Department of Condensed Matter Physics at CUNI MFF, and a lead author of the study.
The article Hydrogen in actinides: electronic and lattice properties provides an overview of the historical development of the investigation of these radioactive metallic elements since the 1940s, but above all, the scientists present the results of their own research. Within it, the physicists managed to explain the changes in electron structure, crystal lattice properties and spectroscopic characteristics due to the incorporation of H atoms into interstitial positions, which leads to volume expansion and charge shifts. The authors also answer questions such as why uranium and plutonium hydrides are ferromagnetic. A special chapter is devoted to the high-temperature superconductivity of polyhydrides.