The understanding of long-term storage of nuclear materials, including plutonium, is essential to avoid risks to human, wildlife and environment. Hydrogen corrosion of plutonium produces plutonium hydride, PuHx, which is a pyrophoric material. We used Density Functional Theory, PBEsol + U approach and Hybrid DFT based on HSE06sol to study fluorite structured PuH2 and cubic PuH3. We explicitly considered spin-orbit coupling and noncollinear magnetic contributions to systematically identify the stability of the magnetic ordering of the hydride structures, resolving the controversy around their magnetic structure. Our findings show that PuHx crystal structures are coupled by spin-orbit interactions to the magnetic states, and that ferromagnetic and antiferromagnetic (longitudinal and transverse) ordering have similar stability and dependent on the Hubbard U parameter used. This result is confirmed by the hybrid DFT. Given the experimental difficulties of handling plutonium hydrides, our results have significant implications in future computational studies of model PuHx systems and related actinide hydrides.

Magnetic properties of cubic plutonium hydrides: A density functional theory study

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.