Noncollinear relativistic DFT+U calculations of actinide dioxide surfaces

DOI: 10.1021/acs.jpcc.8b07823

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

Type: Journal Paper
Journal: The Journal Of Physical Chemistry C

State: Published (Approved)
Published: December 2018

Abstract: A noncollinear relativistic PBEsol+U study of the low-index actinide dioxides (AnO2, An = U, Np, Pu) surfaces has been conducted. The surface properties of the AnO2 have been investigated and the importance of the reorientation of magnetic vectors relative to the plane of the surface is highlighted. In collinear nonrelativistic surface models, the orientation of the magnetic moments is often ignored; however, the use of noncollinear relativistic methods is key to the design of reliable computational models. The ionic relaxation of each surface is shown to be confined to the first three monolayers and we have explored the configurations of the terminal oxygen ions on the reconstructed (001) surface. The reconstructed (001) surfaces are ordered as (001)αβ < (001)α < (001)β in terms of energetics. Electrostatic potential isosurface and scanning tunneling microscopy images have also been calculated. By considering the energetics of the low-index AnO2 surfaces, an octahedral Wulff crystal morphology has been calculated.

Journal Keywords: Crystals; Crystal structure; Ions; Oxygen; Surface energy

Subject Areas: Chemistry, Physics


Technical Areas:

Added On: 10/12/2018 10:52

Discipline Tags:

Surfaces Physics Physical Chemistry Chemistry

Technical Tags: