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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Estimating carrier relaxation times in the Ba8Ga16Ge30 clathrate in the extrinsic regime

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Autor(es):
Gonzalez-Romero, Robert L. ; Antonelli, A.
Número total de Autores: 2
Tipo de documento: Artigo Científico
Fonte: Physical Chemistry Chemical Physics; v. 19, n. 4, p. 3010-3018, 2017.
Citações Web of Science: 5
Resumo

We used a semi-empirical method to extract carrier relaxation times at different temperatures (tau(T)) in thermoelectric materials from a combination of experimental results and first-principles calculations. The methodology is based on the Boltzmann transport equation formalism within the relaxation time approximation. It can be applied to single crystals and polycrystalline materials. We applied the method to investigate the electronic transport properties of the clathrate compound Ba8Ga16Ge30 type-I. The calculations indicate that the carrier relaxation process in single crystals is dominated by electron-phonon scattering (tau proportional to T-3/2), while in polycrystalline materials scattering at grain boundaries dominates (tau similar to cte). The Seebeck coefficient, electrical conductivity, and electron heat conduction are in consistent agreement with experiment. Furthermore, the Slack relation for lattice heat conductivity was successfully applied to the material. The calculated figure of merit is in good agreement with experimental results. (AU)

Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
Beneficiário:Munir Salomao Skaf
Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
Processo FAPESP: 13/14065-7 - Estudo das propriedades eletrônicas, estruturais e de transporte de clatratos para aplicações termoelétricas através de cálculos de primeiros princípios
Beneficiário:Robert Luis González Romero
Linha de fomento: Bolsas no Brasil - Pós-Doutorado