Pressure-driven insulator-metal transition in cubic phase UO 2

Huang, Li; Wang, Yilin; Werner, Philipp

doi:10.1209/0295-5075/119/57007

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Journal article

Pressure-driven insulator-metal transition in cubic phase UO 2

Huang, Li Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang, China
Wang, Yilin Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory, Upton, USA
Werner, Philipp Department of Physics, University of Fribourg, Switzerland

21.11.2017

Published in:

EPL (Europhysics Letters). - 2017, vol. 119, no. 5, p. 57007

English Understanding the electronic properties of actinide oxides under pressure poses a great challenge for experimental and theoretical studies. Here, we investigate the electronic structure of cubic phase uranium dioxide at different volumes using a combination of density functional theory and dynamical mean-field theory. The ab initio calculations predict an orbital-selective insulator-metal transition at a moderate pressure of ∼45 GPa. At this pressure the uranium's 5 f 5/2 state becomes metallic, while the 5 f 7/2 state remains insulating up to about 60 GPa. In the metallic state, we observe a rapid decrease of the 5 f occupation and total angular momentum with pressure. Simultaneously, the so-called “Zhang-Rice state”, which is of predominantly 5 f 5/2 character, quickly disappears after the transition into the metallic phase.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

Language