Effects of filling in CoSb[subscript 3]: Local structure, band gap, and phonons from first principles
Author(s)
Kozinsky, Boris; Wee, Daehyun; Fornari, Marco; Marzari, Nicola
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Alternative title
Effects of filling in CoSb3: Local structure, band gap, and phonons from first principles
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We use ab initio computations to investigate the effect of filler ions on the properties of CoSb3 skutterudites. We analyze global and local structural effects of filling, using the Ba-filled system as an example. We show that the deformation of Sb network induced by the filler affects primarily nearest neighboring Sb sites around the filler site as the soft Sb rings accommodate the distortion. Rearrangement of Sb atoms affects the electronic band structure and we clarify the effect of this local strain on the band gap. We compute the phonon dispersions and identify the filler-dominated modes from the lowest-frequency optical modes at Gamma. Their weak dispersion across the Brillouin zone indicates that they are localized and a force-constant analysis shows that the filler vibration is strongly coupled with nearby Sb atoms.
Date issued
2010-01Department
Massachusetts Institute of Technology. Department of Materials Science and EngineeringJournal
Physical Review B
Publisher
American Physical Society
Citation
Wee, Daehyun et al. “Effects of filling in CoSb[subscript 3] : Local structure, band gap, and phonons from first principles.” Physical Review B 81.4 (2010): 045204. © 2010 The American Physical Society.
Version: Final published version
ISSN
1098-0121
1550-235X