Hidden magnetic order in plutonium dioxide nuclear fuel

DOI: 10.1039/C8CP03583K

Authors: James T. Pegg (University College London; Atomic Weapons Establishment (AWE) Plc) , Ashley E. Shields (Oak Ridge National Laboratory) , Mark T. Storr (Atomic Weapons Establishment (AWE) Plc) , Andrew S. Wills (University College London (UCL)) , David O. Scanlon (University College London; Diamond Light Source) , Nora H. De Leeuw (University College London; Cardiff University)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Physical Chemistry Chemical Physics , VOL 48

State: Published (Approved)
Published: July 2018

Abstract: A thorough understanding of the chemistry of PuO2 is critical to the design of next-generation nuclear fuels and the long-term storage of nuclear materials. Despite over 75 years of study, the ground-state magnetic structure of PuO2 remains a matter of much debate. Experimental studies loosely indicate a diamagnetic (DM) ground-state, whereas theoretical methods have proposed either a collinear ferromagnetic (FM) or anti-ferromagnetic (AFM) ground-state, both of which would be expected to cause a distortion from the reported Fm[3 with combining macron]m symmetry. In this work, we have used accurate calculations based on the density functional theory (DFT) to systematically investigate the magnetic structure of PuO2 to resolve this controversy. We have explicitly considered electron-correlation, spin–orbit interaction and noncollinear magnetic contributions to identify a hereto unknown longitudinal 3k AFM ground-state that retains Fm[3 with combining macron]m crystal symmetry. Given the broad interest in plutonium materials and the inherent experimental difficulties of handling this compound, the results presented in this paper have considerable implications for future computational studies relating to PuO2 and related actinide structures. As the crystal structure is coupled by spin–orbit interactions to the magnetic state, it is imperative to consider relativity when creating computational models.

Subject Areas: Chemistry, Physics, Materials


Technical Areas:

Added On: 02/08/2018 14:14

Documents:
c8cp03583k.pdf

Discipline Tags:

Earth Sciences & Environment Radioactive Materials Physics Physical Chemistry Chemistry Magnetism Materials Science Nuclear Waste

Technical Tags: