The electronic structure of the Te doped CoSb3 skutterudite is investigated by means of fully periodic density functional theory (DFT) calculations. Since the geometrical structure of a material may strongly affect its properties, Te substituted for Sb (Co4Sb11Te) and Te fully filled (TeCo4Sb12) cobalt skutterudite are both studied in order to understand where Te atom is sitting. From the analysis of the geometry and electronic structure properties, the Te filled system is ruled out. The extent of the change transfer among Co, Sb and Te atoms is evaluated using the Quantum Theory of Atom in Molecules (QTAIM). Te substitution for Sb yields a conductor with Fermi energy lying in the conduction bands zone of unsubstituted CoSb3. The Seebeck coefficient S and the electrical conductivity σ are calculated using the semiclassical Boltzmann monoelectronic transport theory. Computed S values agree with experimental evaluations on nanostructured Te doped CoSb3 samples when the frozen band approximation is used for low Te doping and the Co4Sb11Te band structure is adopted for high Te content.
Bertini, L., Billquist, K., Christensen, M., Gatti, C., Holmgren, L., Iversen, B., et al. (2003). Theoretical modeling of Te doped CoSb3. In International Conference on Thermoelectrics, ICT, Proceedings (pp.85-88). 345 E 47TH ST, NEW YORK, NY 10017 USA : Institute of Electrical and Electronics Engineers Inc. [10.1109/ICT.2003.1287455].
Theoretical modeling of Te doped CoSb3
Bertini L.Primo
;
2003
Abstract
The electronic structure of the Te doped CoSb3 skutterudite is investigated by means of fully periodic density functional theory (DFT) calculations. Since the geometrical structure of a material may strongly affect its properties, Te substituted for Sb (Co4Sb11Te) and Te fully filled (TeCo4Sb12) cobalt skutterudite are both studied in order to understand where Te atom is sitting. From the analysis of the geometry and electronic structure properties, the Te filled system is ruled out. The extent of the change transfer among Co, Sb and Te atoms is evaluated using the Quantum Theory of Atom in Molecules (QTAIM). Te substitution for Sb yields a conductor with Fermi energy lying in the conduction bands zone of unsubstituted CoSb3. The Seebeck coefficient S and the electrical conductivity σ are calculated using the semiclassical Boltzmann monoelectronic transport theory. Computed S values agree with experimental evaluations on nanostructured Te doped CoSb3 samples when the frozen band approximation is used for low Te doping and the Co4Sb11Te band structure is adopted for high Te content.
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