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Title: Spin density stabilization of local distortions induced by a monovacancy in δ -Pu

Density functional theory calculations elucidate crystallographic and electronic structural responses of the fcc delta phase of plutonium (δ-Pu) to point defects. Discussed are responses that vary from a defect exhibiting a local structural instability common in fcc metals to an unusual defect structure that mimics properties similar to the monoclinic α phase. In the prior case, the existence of a self-vacancy when ionic relaxation is allowed induces in the fcc lattice a local tetragonal instability in nearest-neighbor atoms, slight electronic charge increase, and a spin-density decrease. However, in the latter case, after ionic relaxation, the defect is not recognizable as the structure of a vacant site common to many simple fcc metals, but is a complex extended defect involving neighboring atoms to collectively exhibit loss of lattice symmetry through formation of short Pu-Pu bonds and associated narrow bands at the Fermi energy. Partial density of states (PDOS) indicates that these narrow bands form as spectral weighting from the less energetic 6d electronic states is shifted to the 5f electronic states by means of the spin density, which occupies states at the Fermi energy. Finally, the PDOS of a 5f system exhibiting narrow bands at the Fermi energy is associated withmore » the formation of an unusual defect structure in the lattice.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
LA-UR-18-23844
Journal ID: ISSN 2475-9953
Grant/Contract Number:
89233218CNA000001
Type:
Accepted Manuscript
Journal Name:
Physical Review Materials
Additional Journal Information:
Journal Volume: 2; Journal Issue: 8; Journal ID: ISSN 2475-9953
Publisher:
American Physical Society (APS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE; LANL Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; distortions & defects; electronic structure; point defects
OSTI Identifier:
1483534
Alternate Identifier(s):
OSTI ID: 1465607

Hernandez, Sarah C., Freibert, Franz J., Hoagland, Richard G., Uberuaga, Blas P., and Wills, John M.. Spin density stabilization of local distortions induced by a monovacancy in δ -Pu. United States: N. p., Web. doi:10.1103/PhysRevMaterials.2.085005.
Hernandez, Sarah C., Freibert, Franz J., Hoagland, Richard G., Uberuaga, Blas P., & Wills, John M.. Spin density stabilization of local distortions induced by a monovacancy in δ -Pu. United States. doi:10.1103/PhysRevMaterials.2.085005.
Hernandez, Sarah C., Freibert, Franz J., Hoagland, Richard G., Uberuaga, Blas P., and Wills, John M.. 2018. "Spin density stabilization of local distortions induced by a monovacancy in δ -Pu". United States. doi:10.1103/PhysRevMaterials.2.085005.
@article{osti_1483534,
title = {Spin density stabilization of local distortions induced by a monovacancy in δ -Pu},
author = {Hernandez, Sarah C. and Freibert, Franz J. and Hoagland, Richard G. and Uberuaga, Blas P. and Wills, John M.},
abstractNote = {Density functional theory calculations elucidate crystallographic and electronic structural responses of the fcc delta phase of plutonium (δ-Pu) to point defects. Discussed are responses that vary from a defect exhibiting a local structural instability common in fcc metals to an unusual defect structure that mimics properties similar to the monoclinic α phase. In the prior case, the existence of a self-vacancy when ionic relaxation is allowed induces in the fcc lattice a local tetragonal instability in nearest-neighbor atoms, slight electronic charge increase, and a spin-density decrease. However, in the latter case, after ionic relaxation, the defect is not recognizable as the structure of a vacant site common to many simple fcc metals, but is a complex extended defect involving neighboring atoms to collectively exhibit loss of lattice symmetry through formation of short Pu-Pu bonds and associated narrow bands at the Fermi energy. Partial density of states (PDOS) indicates that these narrow bands form as spectral weighting from the less energetic 6d electronic states is shifted to the 5f electronic states by means of the spin density, which occupies states at the Fermi energy. Finally, the PDOS of a 5f system exhibiting narrow bands at the Fermi energy is associated with the formation of an unusual defect structure in the lattice.},
doi = {10.1103/PhysRevMaterials.2.085005},
journal = {Physical Review Materials},
number = 8,
volume = 2,
place = {United States},
year = {2018},
month = {8}
}

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