Structural Characterization and Thermoelectric Properties of Br-Doped AgSnm[Sb0.8Bi0.2]Te2+m Systems

Herein, we report the synthesis, structural and microstructural characterization, and thermoelectric properties of AgSnm[Sb0.8Bi0.2]Te2+m and Br-doped telluride systems. These compounds were prepared by solid-state reaction at high temperature. Powder X-ray diffraction data reveal that these samples...

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Detalhes bibliográficos
Autores: Delgado, Daniela; Moris, Silvana; Valencia Gálvez, Paulina; López García, María Luisa; Álvarez Serrano, Inmaculada; Blake, Graeme R.; Galdámez, Antonio
Tipo de documento: Artigo
Data de publicação:2023
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositório:Docta Complutense
Idioma:Inglês
OAI Identifier:oai:docta.ucm.es:20.500.14352/103523
Acesso em linha:https://hdl.handle.net/20.500.14352/103523
Nível de acesso:Acesso aberto
Palavra-chave:546
Tellurides
Seebeck coefficient
Thermal conductivity
Lead-free thermoelectric materials
Performance
SnTe
Thermopower
Power
Química inorgánica (Química)
2303 Química Inorgánica
Descrição
Resumo:Herein, we report the synthesis, structural and microstructural characterization, and thermoelectric properties of AgSnm[Sb0.8Bi0.2]Te2+m and Br-doped telluride systems. These compounds were prepared by solid-state reaction at high temperature. Powder X-ray diffraction data reveal that these samples exhibit crystal structures related to the NaCl-type lattice. The microstructures and morphologies are investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HRTEM). Positive values of the Seebeck coefficient (S) indicate that the transport properties are dominated by holes. The S of undoped AgSnm[Sb0.8Bi0.2]Te2+m ranges from +40 to 57 mu V.K-1. Br-doped samples with m = 2 show S values of +74 mu V.K-1 at RT, and the Seebeck coefficient increases almost linearly with increasing temperature. The total thermal conductivity (kappa(tot)) monotonically increases with increasing temperature (10-300 K). The ktot values of undoped AgSnm[Sb0.8Bi0.2]Te2+m are similar to 1.8 W m(-1) K-1 (m = 4) and similar to 1.0 W m(-1) K-1 (m = 2) at 300 K. The electrical conductivity (sigma) decreases almost linearly with increasing temperature, indicating metal-like behavior. The ZT value increases as a function of temperature. A maximum ZT value of similar to 0.07 is achieved at room temperature for the Br-doped phase with m = 4.